小编The*_*101的帖子

我的代码似乎正确，但我不知道为什么会收到此错误：

未捕获的TypeError：无法读取null的属性“ toUpperCase”

这是我的代码：

    //The function is executed after someone clicks the "Take the Quiz" 
    function startquiz() {
        //The variable for the first question
        var FirstAnwser = prompt("Who posted the first youtube video?");
        //The if statement for the first question
        if (FirstAnwser.toUpperCase()  === 'JAWED KARIM') {
            //If the person is correct a dialog box that says correct pops up
           alert("Correct");
            //The Variable for the second question
            var SecondAnwser = prompt("When was the domain name youtube.com     activated?");
            if (SecondAnwser.toUpperCase() === 'FEBUARY …