overtop = 
  (((navigator.appName == "Netscape") && 
  (parseInt(navigator.appVersion) >= 3 )) || 
  ((navigator.appName == "Microsoft Internet Explorer") && 
  (parseInt(navigator.appVersion) >= 4 )) ||
  ((navigator.appName == "Opera") && 
  (parseInt(navigator.appVersion) >= 8 )));

function imload(img) 
{
  var a=new Image(); a.src=img; return a; 
};// end function


<!--if(overtop) 
{

h2=imload("pics/h2.jpg");

h3=imload("pics/h3.jpg");

h4=imload("pics/h4.jpg");

h6=imload("pics/h6.jpg");

h7=imload("pics/h7.jpg");

h9=imload("pics/h9.jpg");

} 
//-->// END IF


function onimage(a,txt)
{
	if (a){
		document.getElementById('tab0').style.backgroundPosition = txt;	
	}//END IF
	else {
		document.getElementById('tab0').style.backgroundPosition = txt;	
	}//END ELSE
};// END FUNCTION