diff --git a/src/interface/DropDown.cpp b/src/interface/DropDown.cpp
index 6944e6f52..ea7d56a5a 100644
--- a/src/interface/DropDown.cpp
+++ b/src/interface/DropDown.cpp
@@ -5,26 +5,53 @@
  *      Author: Simon
  */
 
+#include <iostream>
+#include "Button.h"
 #include "DropDown.h"
 
 namespace ui {
 
+class ItemSelectedAction;
 class DropDownWindow: public ui::Window {
+	friend class ItemSelectedAction;
 	Colour background, activeBackground;
 	Colour border, activeBorder;
 	Colour text, activeText;
+	DropDown * dropDown;
+	std::vector<Button> buttons;
 	bool isMouseInside;
 public:
-	DropDownWindow(Point position, Point size, Colour background, Colour activeBackground, Colour border, Colour activeBorder, Colour text, Colour activeText):
-		Window(position, size),
-		background(background),
-		activeBackground(activeBackground),
-		border(border),
-		activeBorder(activeBorder),
-		text(text),
-		activeText(activeText)
+	class ItemSelectedAction: public ButtonAction
 	{
-
+		DropDownWindow * window;
+		std::string option;
+	public:
+		ItemSelectedAction(DropDownWindow * window, std::string option): window(window), option(option) { }
+		virtual void ActionCallback(ui::Button *sender)
+		{
+			ui::Engine::Ref().CloseWindow();
+			window->setOption(option);
+			window->SelfDestruct();
+		}
+	};
+	DropDownWindow(DropDown * dropDown):
+		Window(ui::Point(dropDown->Position.X+dropDown->GetParentWindow()->Position.X-5, dropDown->Position.Y+dropDown->GetParentWindow()->Position.Y-3), ui::Point(dropDown->Size.X+10, dropDown->options.size()*13)),
+		dropDown(dropDown),
+		background(background),
+		activeBackground(dropDown->activeBackground),
+		border(dropDown->border),
+		activeBorder(dropDown->activeBorder),
+		text(dropDown->text),
+		activeText(dropDown->activeText)
+	{
+		int currentY = 0;
+		for(int i = 0; i < dropDown->options.size(); i++)
+		{
+			Button * tempButton = new Button(Point(0, currentY), Point(Size.X, 14), dropDown->options[i].first);
+			tempButton->SetActionCallback(new ItemSelectedAction(this, dropDown->options[i].first));
+			AddComponent(tempButton);
+			currentY += 13;
+		}
 	}
 	virtual void OnDraw()
 	{
@@ -32,20 +59,36 @@ public:
 		g->fillrect(Position.X, Position.Y, Size.X, Size.Y, background.Red, background.Green, background.Blue, 255);
 		g->drawrect(Position.X, Position.Y, Size.X, Size.Y, border.Red, border.Green, border.Blue, 255);
 	}
+	void setOption(std::string option)
+	{
+		dropDown->SetOption(option);
+		if(dropDown->callback)
+		{
+			int optionIndex = 0;
+			for(optionIndex = 0; optionIndex < dropDown->options.size(); optionIndex++)
+			{
+				if(option == dropDown->options[optionIndex].first)
+					break;
+			}
+			dropDown->callback->OptionChanged(dropDown, dropDown->options[optionIndex]);
+		}
+	}
 	virtual ~DropDownWindow() {}
 };
 
 DropDown::DropDown(Point position, Point size):
 	Component(position, size),
-	isMouseInside(false)
+	isMouseInside(false),
+	optionIndex(-1)
 {
-	activeText = background = Colour(0, 0, 0);
-	text = activeBackground = border = activeBorder = Colour(255, 255, 255);
+	background = activeBackground = Colour(0, 0, 0);
+	activeText = text = activeBackground = border = activeBorder = Colour(255, 255, 255);
 }
 
 void DropDown::OnMouseClick(int x, int y, unsigned int button)
 {
-	ui::Engine().Ref().ShowWindow(new DropDownWindow(ui::Point(50, 50), ui::Point(50, 50), background, activeBackground, border, activeBorder, text, activeText));
+	DropDownWindow * newWindow = new DropDownWindow(this);
+	ui::Engine().Ref().ShowWindow(newWindow);
 }
 
 void DropDown::Draw(const Point& screenPos)
@@ -56,20 +99,73 @@ void DropDown::Draw(const Point& screenPos)
 	{
 		g->fillrect(Position.X-1, Position.Y-1, Size.X+2, Size.Y+2, activeBackground.Red, activeBackground.Green, activeBackground.Blue, 255);
 		g->drawrect(Position.X, Position.Y, Size.X, Size.Y, activeBorder.Red, activeBorder.Green, activeBorder.Blue, 255);
+		if(optionIndex!=-1)
+			g->drawtext(Position.X, Position.Y+1, options[optionIndex].first, activeText.Red, activeText.Green, activeText.Blue, 255);
 		//g->drawtext(Position.X+textPosition.X, Position.Y+textPosition.Y+1, displayText, activeText.Red, activeText.Green, activeText.Blue, 255);
 	}
 	else
 	{
 		g->fillrect(Position.X, Position.Y, Size.X, Size.Y, background.Red, background.Green, background.Blue, 255);
 		g->drawrect(Position.X, Position.Y, Size.X, Size.Y, border.Red, border.Green, border.Blue, 255);
+		if(optionIndex!=-1)
+			g->drawtext(Position.X, Position.Y+1, options[optionIndex].first, text.Red, text.Green, text.Blue, 255);
 		//g->drawtext(Position.X+textPosition.X, Position.Y+textPosition.Y+1, displayText, text.Red, text.Green, text.Blue, 255);
 	}
 
 }
+	
+	void DropDown::SetOption(std::string option)
+	{
+		for(int i = 0; i < options.size(); i++)
+		{
+			if(options[i].first == option)
+			{
+				optionIndex = i;
+				return;
+			}
+		}
+	}
+	void DropDown::SetOption(int option)
+	{
+		for(int i = 0; i < options.size(); i++)
+		{
+			if(options[i].second == option)
+			{
+				optionIndex = i;
+				return;
+			}
+		}
+	}
+	void DropDown::AddOption(std::pair<std::string, int> option)
+	{
+		for(int i = 0; i < options.size(); i++)
+		{
+			if(options[i] == option)
+				return;
+		}
+		options.push_back(option);
+	}
+	void DropDown::RemoveOption(std::string option)
+	{
+	start:
+		for(int i = 0; i < options.size(); i++)
+		{
+			if(options[i].first == option)
+			{
+				options.erase(options.begin()+i);
+				goto start;
+			}
+		}
+	}
+	void DropDown::SetOptions(std::vector<std::pair<std::string, int> > options)
+	{
+		this->options = options;
+	}
 
 
 DropDown::~DropDown() {
-	// TODO Auto-generated destructor stub
+	if(callback)
+		delete callback;
 }
 
 } /* namespace ui */
diff --git a/src/interface/DropDown.h b/src/interface/DropDown.h
index 619ec5a3b..34310df7d 100644
--- a/src/interface/DropDown.h
+++ b/src/interface/DropDown.h
@@ -8,18 +8,37 @@
 #ifndef DROPDOWN_H_
 #define DROPDOWN_H_
 
+#include <utility>
 #include "Component.h"
 #include "Colour.h"
 
 namespace ui {
 
+class DropDown;
+class DropDownWindow;
+class DropDownAction
+{
+public:
+	virtual void OptionChanged(DropDown * sender, std::pair<std::string, int> newOption) {}
+	virtual ~DropDownAction() {}
+};
 class DropDown: public ui::Component {
+	friend class DropDownWindow;
 	Colour background, activeBackground;
 	Colour border, activeBorder;
 	Colour text, activeText;
 	bool isMouseInside;
+	int optionIndex;
+	DropDownAction * callback;
+	std::vector<std::pair<std::string, int> > options;
 public:
 	DropDown(Point position, Point size);
+	void SetOption(int option);
+	void SetOption(std::string option);
+	void AddOption(std::pair<std::string, int> option);
+	void RemoveOption(std::string option);
+	void SetOptions(std::vector<std::pair<std::string, int> > options);
+	void SetActionCallback(DropDownAction * action) { callback = action;}
 	virtual void Draw(const Point& screenPos);
 	virtual void OnMouseClick(int x, int y, unsigned int button);
 	virtual ~DropDown();
diff --git a/src/interface/Window.cpp b/src/interface/Window.cpp
index 2de646383..86221ab0e 100644
--- a/src/interface/Window.cpp
+++ b/src/interface/Window.cpp
@@ -26,6 +26,7 @@ Window::~Window()
 			if(Components[i]==focusedComponent_)
 				focusedComponent_ = NULL;
 		}
+	Components.clear();
 }
 
 void Window::AddComponent(Component* c)
diff --git a/src/options/OptionsController.cpp b/src/options/OptionsController.cpp
index b39509cd9..85f2a2ffc 100644
--- a/src/options/OptionsController.cpp
+++ b/src/options/OptionsController.cpp
@@ -38,6 +38,14 @@ void OptionsController::SetWaterEqualisation(bool state)
 {
 	model->SetWaterEqualisation(state);
 }
+void OptionsController::SetGravityMode(int gravityMode)
+{
+	model->SetGravityMode(gravityMode);
+}
+void OptionsController::SetAirMode(int airMode)
+{
+	model->SetAirMode(airMode);
+}
 
 OptionsView * OptionsController::GetView()
 {
diff --git a/src/options/OptionsController.h b/src/options/OptionsController.h
index 18bbf4ede..19f0e9b4c 100644
--- a/src/options/OptionsController.h
+++ b/src/options/OptionsController.h
@@ -26,6 +26,8 @@ public:
 	void SetAmbientHeatSimulation(bool state);
 	void SetNewtonianGravity(bool state);
 	void SetWaterEqualisation(bool state);
+	void SetGravityMode(int gravityMode);
+	void SetAirMode(int airMode);
 	void Exit();
 	OptionsView * GetView();
 	virtual ~OptionsController();
diff --git a/src/options/OptionsModel.cpp b/src/options/OptionsModel.cpp
index c0a69f530..3891d41d6 100644
--- a/src/options/OptionsModel.cpp
+++ b/src/options/OptionsModel.cpp
@@ -5,6 +5,7 @@
  *      Author: Simon
  */
 
+#include "Air.h"
 #include "OptionsModel.h"
 
 OptionsModel::OptionsModel(Simulation * sim_) {
@@ -64,6 +65,26 @@ void OptionsModel::SetWaterEqualisation(bool state)
 	notifySettingsChanged();
 }
 
+int OptionsModel::GetAirMode()
+{
+	return sim->air->airMode;
+}
+void OptionsModel::SetAirMode(int airMode)
+{
+	sim->air->airMode = airMode;
+	notifySettingsChanged();
+}
+
+int OptionsModel::GetGravityMode()
+{
+	return sim->gravityMode;
+}
+void OptionsModel::SetGravityMode(int gravityMode)
+{
+	sim->gravityMode = gravityMode;
+	notifySettingsChanged();
+}
+
 void OptionsModel::notifySettingsChanged()
 {
 	for(int i = 0; i < observers.size(); i++)
diff --git a/src/options/OptionsModel.h b/src/options/OptionsModel.h
index 903f3b737..8f83fc8a1 100644
--- a/src/options/OptionsModel.h
+++ b/src/options/OptionsModel.h
@@ -28,6 +28,10 @@ public:
 	void SetNewtonianGravity(bool state);
 	bool GetWaterEqualisation();
 	void SetWaterEqualisation(bool state);
+	int GetAirMode();
+	void SetAirMode(int airMode);
+	int GetGravityMode();
+	void SetGravityMode(int gravityMode);
 	virtual ~OptionsModel();
 };
 
diff --git a/src/options/OptionsView.cpp b/src/options/OptionsView.cpp
index d863844de..d1066a84b 100644
--- a/src/options/OptionsView.cpp
+++ b/src/options/OptionsView.cpp
@@ -8,6 +8,7 @@
 #include "OptionsView.h"
 #include "interface/Button.h"
 #include "interface/Label.h"
+#include "interface/DropDown.h"
 
 OptionsView::OptionsView():
 	ui::Window(ui::Point(-1, -1), ui::Point(300, 300)){
@@ -77,14 +78,42 @@ OptionsView::OptionsView():
 	tempLabel->SetAlignment(AlignLeft, AlignMiddle);
 	AddComponent(tempLabel);
 
-	airMode = new ui::DropDown(ui::Point(Size.X-55, 143), ui::Point(50, 16));//, "Water equalisation \bgIntroduced in version 61");
-	//airMode->SetActionCallback(new WaterEqualisationAction(this));
+	class AirModeChanged: public ui::DropDownAction
+	{
+		OptionsView * v;
+	public:
+		AirModeChanged(OptionsView * v): v(v) { }
+		virtual void OptionChanged(ui::DropDown * sender, std::pair<std::string, int> option) { v->c->SetAirMode(option.second); }
+	};
+	airMode = new ui::DropDown(ui::Point(Size.X-85, 143), ui::Point(80, 16));
 	AddComponent(airMode);
-	tempLabel = new ui::Label(ui::Point(3, 143), ui::Point(Size.X-24, 16), "Air Simulation Mode");
+	airMode->AddOption(std::pair<std::string, int>("On", 0));
+	airMode->AddOption(std::pair<std::string, int>("Pressure off", 1));
+	airMode->AddOption(std::pair<std::string, int>("Velocity off", 2));
+	airMode->AddOption(std::pair<std::string, int>("Off", 3));
+	airMode->AddOption(std::pair<std::string, int>("No Update", 4));
+	airMode->SetActionCallback(new AirModeChanged(this));
+		
+	tempLabel = new ui::Label(ui::Point(3, 143), ui::Point(Size.X-90, 16), "Air Simulation Mode");
 	tempLabel->SetAlignment(AlignLeft, AlignMiddle);
 	AddComponent(tempLabel);
+		
+	class GravityModeChanged: public ui::DropDownAction
+	{
+		OptionsView * v;
+	public:
+		GravityModeChanged(OptionsView * v): v(v) { }
+		virtual void OptionChanged(ui::DropDown * sender, std::pair<std::string, int> option) { v->c->SetGravityMode(option.second); }
+	};	
+		
+	gravityMode = new ui::DropDown(ui::Point(Size.X-85, 163), ui::Point(80, 16));
+	AddComponent(gravityMode);
+	gravityMode->AddOption(std::pair<std::string, int>("Vertical", 0));
+	gravityMode->AddOption(std::pair<std::string, int>("Off", 1));
+	gravityMode->AddOption(std::pair<std::string, int>("Radial", 2));
+	gravityMode->SetActionCallback(new GravityModeChanged(this));
 
-	tempLabel = new ui::Label(ui::Point(3, 163), ui::Point(Size.X-24, 16), "Gravity Simulation Mode");
+	tempLabel = new ui::Label(ui::Point(3, 163), ui::Point(Size.X-90, 16), "Gravity Simulation Mode");
 	tempLabel->SetAlignment(AlignLeft, AlignMiddle);
 	AddComponent(tempLabel);
 
@@ -111,6 +140,8 @@ void OptionsView::NotifySettingsChanged(OptionsModel * sender)
 	ambientHeatSimulation->SetChecked(sender->GetAmbientHeatSimulation());
 	newtonianGravity->SetChecked(sender->GetNewtonianGravity());
 	waterEqualisation->SetChecked(sender->GetWaterEqualisation());
+	airMode->SetOption(sender->GetAirMode());
+	gravityMode->SetOption(sender->GetGravityMode());
 }
 
 void OptionsView::AttachController(OptionsController * c_)
diff --git a/src/simulation/SaveLoader.cpp b/src/simulation/SaveLoader.cpp
index b07ba08c7..7db6895f0 100644
--- a/src/simulation/SaveLoader.cpp
+++ b/src/simulation/SaveLoader.cpp
@@ -7,6 +7,7 @@
 
 #include <bzlib.h>
 #include <cmath>
+#include "Air.h"
 #include "SaveLoader.h"
 
 //!TODO: enum for LoadSave return
@@ -118,7 +119,7 @@ int SaveLoader::PSVLoad(unsigned char * data, int dataLength, Simulation * sim,
 			}
 			if (ver>=46 && replace) {
 				sim->gravityMode = ((c[3]>>2)&0x03);// | ((c[3]>>2)&0x01);
-				sim->airMode = ((c[3]>>4)&0x07);// | ((c[3]>>4)&0x02) | ((c[3]>>4)&0x01);
+				sim->air->airMode = ((c[3]>>4)&0x07);// | ((c[3]>>4)&0x02) | ((c[3]>>4)&0x01);
 			}
 			if (ver>=49 && replace) {
 				tempGrav = ((c[3]>>7)&0x01);
@@ -170,7 +171,7 @@ int SaveLoader::PSVLoad(unsigned char * data, int dataLength, Simulation * sim,
 	{
 		if (ver<46) {
 			sim->gravityMode = 0;
-			sim->airMode = 0;
+			sim->air->airMode = 0;
 		}
 		sim->clear_sim();
 	}
@@ -904,7 +905,7 @@ unsigned char * SaveLoader::PSVBuild(int & dataLength, Simulation * sim, int ori
 	c[0] = 0x50;	//0x66;
 	c[1] = 0x53;	//0x75;
 	c[2] = 0x76;	//0x43;
-	c[3] = sim->legacy_enable|((sim->sys_pause<<1)&0x02)|((sim->gravityMode<<2)&0x0C)|((sim->airMode<<4)&0x70)|((sim->ngrav_enable<<7)&0x80);
+	c[3] = sim->legacy_enable|((sim->sys_pause<<1)&0x02)|((sim->gravityMode<<2)&0x0C)|((sim->air->airMode<<4)&0x70)|((sim->ngrav_enable<<7)&0x80);
 	c[4] = SAVE_VERSION;
 	c[5] = CELL;
 	c[6] = bw;
diff --git a/src/simulation/Simulation.h b/src/simulation/Simulation.h
index f4f8f5b70..d200106b2 100644
--- a/src/simulation/Simulation.h
+++ b/src/simulation/Simulation.h
@@ -202,7 +202,7 @@ public:
 	int photons[YRES][XRES];
 	//
 	int gravityMode;
-	int airMode;
+	//int airMode;
 	int ngrav_enable;
 	int legacy_enable;
 	int aheat_enable;