$(document).ready(function ()
{

   $('#performanceSearch').click(function (){
		var checkboxArr = $("input:checked");
		var result1 = "";
		var result = "";
		if(checkboxArr.length<1)
		{
		  alert("请选择性能");
		  return false;
		}
		for (var i = 0; i < checkboxArr.length; i++) {
			result1 = result1 + "-" + checkboxArr[i].value;
			result = result + "," + checkboxArr[i].value;
			if(i>2)
			{
			  alert("最多只能选择3种性能");
			  return false;
			}
		}
    	$('#hperformance').attr("value",result);
		/* GA-Eventrack Begin */
		var cdStr2 = result1;
		pageTracker._trackEvent("Michelin-Tire-Selector", "By-performance", cdStr2);
		/* GA-Eventrack End */
       document.performanceform.submit();
     });      

 });