diff --git a/phpBB/styles/subSilver/template/editor.js b/phpBB/styles/subSilver/template/editor.js
index c6542aac89..60c1b30013 100644
--- a/phpBB/styles/subSilver/template/editor.js
+++ b/phpBB/styles/subSilver/template/editor.js
@@ -19,7 +19,7 @@ var is_win = ((clientPC.indexOf('win') != -1) || (clientPC.indexOf('16bit') != -
 var is_mac = (clientPC.indexOf('mac') != -1);
 
 var baseHeight;
-window.onload = initInsertions;
+window.onload = initInsertions();
 
 /**
 * Shows the help messages in the helpline window
@@ -73,10 +73,13 @@ function arraypop(thearray)
 */ 
 function initInsertions() 
 {
-	document.post.message.focus();
-	if (is_ie && typeof(baseHeight) != 'number')
+	if(is_ie)
 	{
-		baseHeight = document.selection.createRange().duplicate().boundingHeight;
+		document.post.message.focus();
+		if (is_ie && typeof(baseHeight) != 'number')
+		{
+			baseHeight = document.selection.createRange().duplicate().boundingHeight;
+		}
 	}
 }