$(document).ready( function () {
    var tagObj = $j("#main ul.thumbnail li").get();
	var tagObjLeng = tagObj.length
    var tagInclude = 20-tagObjLeng
	if(20 > tagObjLeng){
        for(var i=0; i<tagInclude; i++){
            $j("#main ul.thumbnail").append('<li class="noimage">&nbsp;</li>');
        }
    }
});