function fillCategory(){
	//decided for those do not hv record's category
	//for example, mono-ringtone
	var x=document.getElementById("category");
	if(x){
		var child = x.getElementsByTagName("LI");
		var blankLI = '';
		for(var i=0; i<child.length; i++){
			if(child[i].getElementsByTagName("A")[0].innerHTML.length<1){
				child[i].style.display = 'none';
			}
		}
		for (var i=0; i<(3-(child.length%3)); i++ ){
			blankLI += '<LI class="category_blank"><a>&nbsp;</a></LI>';
		}
		if (x.getElementsByTagName("UL").length > 0)
			x.getElementsByTagName("UL")[0].innerHTML += blankLI;
	}
}