jQuery 문자열 자르기

$(".stab > a").each(function(index) {
	var $this = $(this);
	var tid = $this.attr("id");
	var spid = $this.parents().parents().attr("id");
	var snum = spid.substring(spid.length - 1);
	$this.bind("click",function(){
		$this.addClass("active").siblings().removeClass("active");
		$("#spbox"+ snum +"").load("./"+tid+".php");
		return false;
	});
});