function $(_id){return document.getElementById(_id);}
 function changeStatus(_indexNum){
	var areaObj=$("v"+_indexNum);
	var areaTitle=$("v"+_indexNum+"_title");
	var areaImg=$("v"+_indexNum+"_img");
	var areaCont=$("v"+_indexNum+"_cont");
	if(areaCont.className=="show"){
		areaImg.src="../images/plus.gif";
		areaImg.alt="减号";
		areaCont.className="hide";
	}else{
		areaImg.src="../images/minus.gif";
		areaImg.alt="加号";
		areaCont.className="show";
	}
 }