如何通过javaScript从下拉列表中获取选定的值

Question

I'm trying to code the javascript to change the javascript file src to get selected animation on background. Here's what I'm trying to do. It would be appreciated if you would give me the right coding. Thank you so much! ^ - ^

<select id="select" onchange="changeScript();">

        <option value="js/style0.js" selected="selected">Basic</option>
        <option value="js/style1.js">Spring</option>
        <option value="js/style2.js">Summer</option>
        <option value="js/style3.js">Autumn</option>
        <option value="js/style4.js">Winter</option>

</select>

<script src="js/style.js" type="text/javascript" id="myscript"></script>
<script type="text/javascript"><!--
    function changeScript(jsfile) {
      document.getElementById('myscript').src = jsfile;
   }
// --></script>

Answer 1

You can use the selectedIndexy property to get the selected value from dropdown, something like

function changeScript() {   
    var select = document.getElementById("select"); //getting select element
    var jsfile = select.options[select.selectedIndex].value;
     //--------getting the selected value-------------^
    document.getElementById('myscript').src = jsfile;
}

UPDATE

DEMO

Answer 2

You have defined a function changeScript(jsfile) but you are not passing any value. It should at least be:

<select id="select" onchange="changeScript(this.value);">