function chkSize(frm){
	if(frm.sku.selectedIndex==0){
		alert("You must select a size first");
		return false;
	}
	return true;
}

function bigImage(obj,which){
	var pos=getObjPos(obj);
	$('big_image').innerHTML='<img src="/images/custom/'+which+'.jpg" />';
	$('big_image').style.left=pos.x+'px';
	$('big_image').style.top=pos.y+'px';
}