if (document.images){
     sub1off= new Image(80,16);
     sub1off.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/forcomputing-0.gif";
     sub1on= new Image(80,16); 
     sub1on.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/forcomputing-1.gif"; 
     
     sub2off= new Image(70,16);
     sub2off.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/forstudents-0.gif";
     sub2on= new Image(70,16); 
     sub2on.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/forstudents-1.gif";
     
     sub3off= new Image(48,16);
     sub3off.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/forstaff-0.gif";
     sub3on= new Image(48,16); 
     sub3on.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/forstaff-1.gif";

     sub4off= new Image(160,16);
     sub4off.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/ohs-0.gif";
     sub4on= new Image(160,16)  
     sub4on.src="/system/modules/au.edu.unsw.cse.new/resources/submenu/help/ohs-1.gif";
}

function submenuTurnOn(imgName){
   if (document.images){
      imgOn=eval(imgName + "on.src");
      document[imgName].src= imgOn;
   }
 }

function submenuTurnOff(imgName){
   if (document.images){
      imgOff=eval(imgName + "off.src");
      document[imgName].src= imgOff;
   }
}