function getbyid(id) {
	return document.getElementById(id);
}

function tabmenu (pre,id,num){
	for (var i = 1 ; i <= num ; i ++ ){
		var t = pre + i ;
		var tab = pre + 'tab_' + i ;
		if (i == id){
			getbyid(t).className = "set";
			
			getbyid(tab).filters[0].Apply();
			getbyid(tab).style.display = "";
			getbyid(tab).filters[0].Play(duration=0.5);
		}else{
			getbyid(t).className = "";
			getbyid(tab).style.display = "none";
		}
	}
}