diff --git a/mod/scorm/datamodels/scorm_13lib.php b/mod/scorm/datamodels/scorm_13lib.php
index 53656c14df7..6cef7b05656 100644
--- a/mod/scorm/datamodels/scorm_13lib.php
+++ b/mod/scorm/datamodels/scorm_13lib.php
@@ -119,7 +119,7 @@ function scorm_get_toc($user,$scorm,$liststyle,$currentorg='',$scoid='',$mode='n
                 if (isset($_COOKIE['hide:SCORMitem'.$nextsco->id])) {
                     $icon = 'plus';
                 }
-                $result->toc .= "\t\t".'<li><a href="javascript:expandCollide(img'.$sublist.',s'.$sublist.','.$nextsco->id.');">'.
+                $result->toc .= "\t\t".'<li><a href="javascript:expandCollide(\'img'.$sublist.'\',\'s'.$sublist.'\','.$nextsco->id.');">'.
                                 '<img id="img'.$sublist.'" src="'.$scormpixdir.'/'.$icon.'.gif" alt="'.$strexpand.'" title="'.$strexpand.'"/></a>';
             } else if ($isvisible) {
                 $result->toc .= "\t\t".'<li><img src="'.$scormpixdir.'/spacer.gif" />';
@@ -228,15 +228,16 @@ function scorm_get_toc($user,$scorm,$liststyle,$currentorg='',$scoid='',$mode='n
               function expandCollide(which,list,item) {
                   var nn=document.ids?true:false
                   var w3c=document.getElementById?true:false
-                  var beg=nn?"document.ids.":w3c?"document.getElementById(":"document.all.";
-                  var mid=w3c?").style":".style";
+                  var beg=nn?"document.ids.":w3c?"document.getElementById(\'":"document.all.";
+                  var mid=w3c?"\').style":".style";
 
+                  which = which.substring(0,(which.length));
                   if (eval(beg+list+mid+".display") != "none") {
-                      which.src = "'.$scormpixdir.'/plus.gif";
+                      document.getElementById(which).src = "'.$scormpixdir.'/plus.gif";
                       eval(beg+list+mid+".display=\'none\';");
                       new cookie("hide:SCORMitem" + item, 1, 356, "/").set();
                   } else {
-                      which.src = "'.$scormpixdir.'/minus.gif";
+                      document.getElementById(which).src = "'.$scormpixdir.'/minus.gif";
                       eval(beg+list+mid+".display=\'block\';");
                       new cookie("hide:SCORMitem" + item, 1, -1, "/").set();
                   }