IE - Invalid Argument

[thehuggableone]

I've had my round with this page for the past few days and can't
figure out why I'm getting this error. Any help would be wonderful.
When you mouse over stuff in IE you get an Invalid Argument error.

http://65.61.134.86/tour.asp?ctSelect=0

The code that it shows me when it breaks is:

function zot_on(zid){
if(zid != zotOn){
//Breaks here
$("ct_zot_"+zid).style.backgroundImage = "url('/images/ct_zot_" +
zid + ".jpg');"
$("ct_zot_"+zid).style.backgroundRepeat = "no-repeat;"
}
}

Thanks