Javascript 韩元'；不能正确更改iframe src

我最近开始对JS感兴趣，一直在胡闹。我在HTML代码中嵌入了一些JS，我想知道为什么它不能正常工作。代码似乎总是将

src

更改为

http://www.learn ... 无论选择哪一个框，都要填入mult_seven.xml

。测试这个

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函数转换游戏（）{
var e=document.getElementById（“timestableSlt”）；
var strUser=e.options[e.selectedIndex].text；
如果（strUser=“1”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_one.xml";
}否则，如果（strUser=“2”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_two.xml";
}否则，如果（strUser=“3”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_three.xml";
}否则，如果（strUser=“4”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_four.xml";
}否则，如果（strUser=“5”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_five.xml";
}否则，如果（strUser=“7”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_seven.xml";
}否则，如果（strUser=“8”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_eight.xml";
}否则，如果（strUser=“9”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_nine.xml";
}否则，如果（strUser=“10”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_ten.xml";
}否则，如果（strUser=“11”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_eleven.xml";
}否则，如果（strUser=“12”）{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_twelve.xml";
}否则{
document.getElementById（'multGame'）。src=”http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_six.xml";
}
}

将strUser的值设置为“1”，并重复该过程，将其设置为n+1，直到到达最后一个else if语句，这就是strUser始终等于12的原因

如果要比较值（而不是设置值），则需要使用两个等号

---

问题在于您的比较

=

。相反，使用strUser==“5”

问题在于您的比较“=”。。。。使用'strUser==“5”@CMedina我试试看@那是有效的。谢谢如果你把它贴出来，我会接受你的回答；-）另外，您应该将

selected=“selected”

更改为just

selected

@TheMintyMate好的，我只是按照W3s说的做了。我会改变的。。。

        <iframe height="400" width="600" id="multGame" src="http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_six.xml"></iframe>


        <select id="timestableSlt" onchange="changeGame()">
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="6" selected="selected">6</option>
            <option value="7">7</option>
            <option value="8">8</option>
            <option value="9">9</option>
            <option value="10">10</option>
            <option value="11">11</option>
            <option value="12">12</option>
        </select> 
        <script>
        function changeGame() {
            var e = document.getElementById("timestableSlt");
            var strUser = e.options[e.selectedIndex].text;


            if (strUser = "1") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_one.xml";
            } else if (strUser = "2") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_two.xml";
            } else if (strUser = "3") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_three.xml";
            } else if (strUser = "4") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_four.xml";
            } else if (strUser = "5") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_five.xml";
            } else if (strUser = "7") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_seven.xml";
            } else if (strUser = "8") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_eight.xml";
            } else if (strUser = "9") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_nine.xml";
            } else if (strUser = "10") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_ten.xml";
            } else if (strUser = "11") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_eleven.xml";
            } else if (strUser = "12") {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_twelve.xml";
            } else {
            document.getElementById('multGame').src = "http://www.learninggamesforkids.com/_games/Main.swf?xml=assets/fill_in_blanks/fillitin_mult_six.xml";
            }
        }
        </script>

strUser = "1"

strUser == "1"