JS错误定位方法

<script>

window.onerror = function(sMessage,sUrl,sLine){

    var str = "";

    str += " 错误信息:" + sMessage + "/n";

    str += " 错误地址:" + sUrl + "/n";

    str += " 错误行数:" + sLine + "/n";

    str += "<=========调用堆栈=========>/n";

    var func = window.onerror.caller;

    var index = 0;

    while(func!=null){

       str += "第" + index + "个函数：" + func + "/n";

       str += "第" + index + "个函数：参数表："

       for(var i=0;i<func.arguments.length;i++){

           str += func.arguments[i] + ",";

       }

       str += "/n===================/n";

       func = func.caller;

       index++;

    }

    alert(str);

}

function test(){

    test1("a","b");

}

function test1(a,b){

    alert(ab);

}

test();

</script>