菜鸟求解？

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script language="javascript" type="text/javascript">
   function googlesearch()
           {
              var wq = document.getElementsByName("wq")[0].value;
              var link = "http://www.google.com/search?domains=www.williamlong.info&sitesearch=www.williamlong.info&q=" + wq;
              window.open(link);
          }
          function baidusearch()
            {
                    var wd=document.getElementsByName("wq")[0].value;
                    var link="http://www.baidu.com/s?si=www.williamlong.info&cl=3&ct=2097152&tn=baidulocal&word="+wq;
                    window.open(link);
             }
             window.onload = function () {
                 var province = document.getElementById("Select1");
                 var pindex = province.selectedIndex;
                 var pValue = province.options[pindex].value;
                 if (pValue == 0) {
                     g.value = "Google  搜索";
                     g.onclick = "javascript:googlesearch()";
                 } else if (pValue == 1) {
                     g.value = "百度一下";
                     g.onclick = "javascript:baiduesearch()";
                 }
             }
</script>
    <title></title>
</head><body id="a">
    <select id="Select1" name="D1" >
        <option value="0">Google  搜索</option>
        <option value="1">百度一下</option>
    </select>

<input type="text" name="wq"/>
<input id="g" type="submit"  onclick = "javascript:googlesearch()" value="Google 搜索"/>
</body>
</html>切换select下拉菜单的值是百度一下时，submit的value值变了但是不刷新还是google 搜索怎样才能做到不刷新就可以实现点击select的选项，submit显示对应的值，还有onclick  点击时为什么不跳转到百度或是google，

解决方案 »

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nclick = "javascript:googlesearch()" 应该是：nclick = "googlesearch()"<script language="javascript" type="text/javascript">
    window.onload = function () {
        var Select = document.getElementById("Select1");
        var g = document.getElementById("g");
        Select.onchange=function(){
            if(this.value==0){
                g.value = "Google  搜索";
                g.onclick = function(){
                    find(0);
                };
            }else{
                g.value = "百度一下";
                g.onclick = function(){
                    find(1);
                };
            }
        };
    };
    function find(id){
        var wq=document.getElementsByName("wq")[0].value;
        if(wq==""){
            alert("关键词不能为空！");
            document.getElementsByName("wq")[0].focus();
        }else{
            var link=id==0?"http://www.google.com.hk/search?domains=www.williamlong.info&sitesearch=www.williamlong.info&q=" + wq:"http://www.baidu.com/s?si=www.williamlong.info&cl=3&ct=2097152&tn=baidulocal&word="+wq;
            window.open(link);
        }
    }
</script>
<select id="Select1" name="D1" >
    <option value="0">Google  搜索</option>
    <option value="1">百度一下</option>
</select>
<input type="text" name="wq"/>
<input id="g" type="button" onclick="find(0)"  value="Google 搜索"/>
你需要再select元素上面，绑定一个onchange的事件，否则没有办法select的选择，不管你选择百度，或者谷歌，搜索都是进行的谷歌搜索。在onchange函数内，根据select的选择内容，改变后面的搜索按钮的执行函数，分别执行百度的那个函数，或者是谷歌的函数。
你写的可以无刷新改变，但是还有个问题，当你select百度一下时如果刷新一下页面submit的value又会回到google 搜索，这个怎么解决？
这是只html，除非你用cookie存起来。<script language="javascript" type="text/javascript">
    window.onload = function () {
        var Select = document.getElementById("Select1");
        var g = document.getElementById("g");
        Select.onchange=function(){
            SetCookie("scs",this.value);
            if(this.value==0){
                g.value = "Google  搜索";
                g.onclick = function(){
                    find();
                };
            }else{
                g.value = "百度一下";
                g.onclick = function(){
                    find();
                };
            }
        };
        if(getCookie("scs")=="1"){
            g.value = "百度一下";
            Select.value=1;
        }
    };
    function find(){
        var id=getCookie("scs");
        var wq=document.getElementsByName("wq")[0].value;
        if(wq==""){
            alert("关键词不能为空！");
            document.getElementsByName("wq")[0].focus();
        }else{
            var link=id=="0"?"http://www.google.com.hk/search?domains=www.williamlong.info&sitesearch=www.williamlong.info&q=" + wq:"http://www.baidu.com/s?si=www.williamlong.info&cl=3&ct=2097152&tn=baidulocal&word="+wq;
            window.open(link);
        }
    }
    function SetCookie(name,value){
        var Days = 30;
        var exp = new Date();
        exp.setTime(exp.getTime() + Days*24*60*60*1000);
        document.cookie = name + "="+ value + ";expires=" + exp.toGMTString();
    }
    function getCookie(name){
        var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
        if(arr != null) return unescape(arr[2]); return null;
    }
</script>
<select id="Select1" name="D1" >
    <option value="0">Google  搜索</option>
    <option value="1">百度一下</option>
</select>
<input type="text" name="wq"/>
<input id="g" type="button" onclick="find()"  value="Google 搜索"/>
换个思路不就好办了点击事件中判断select 选择值，
不同值，拼接不同url
动态修改表单的 action
或者，直接 open
没必要修改点击事件。
我分别对你的问题分别进行回答：
你问为什么，点击按钮不跳转，
你去掉 id="g"就可以了
另外你问怎么改变Button的值，其实很简单，
在你的代码基础上，稍加修改就可以了。。
其实，就是调用了select的onchange事件，而不是调用window的onload方法。

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript"> function googlesearch()
           {
alert(2);
              var wq = document.getElementsByName("wq")[0].value;
              var link = "http://www.google.com/search?domains=www.williamlong.info&sitesearch=www.williamlong.info&q=" + wq;
              window.location.href = (link);
          }
          function baidusearch()
            {
                    var wd=document.getElementsByName("wq")[0].value;
                    var link="http://www.baidu.com/s?si=www.williamlong.info&cl=3&ct=2097152&tn=baidulocal&word="+wq;
                    window.open(link);
             }             function selectOnChange() {
                 var province = document.getElementById("Select1");
                 var pindex = province.selectedIndex;
alert(pindex)
                 var pValue = province.options[pindex].value;
                 if (pValue == 0) {
                     g.value = "Google  搜索";
                     g.onclick = "javascript:googlesearch()";
                 } else if (pValue == 1) {
                     g.value = "百度一下";
                     g.onclick = "javascript:baiduesearch()";
                 }
             }

</script>
    <title></title>
</head><body id="a">
    <select id="Select1" onchange="selectOnChange()" name="D1" >
        <option value="0">Google  搜索</option>
        <option value="1">百度一下</option>
    </select>

<input type="text" name="wq"/>
<input id="g"  type="button"  onclick="googlesearch()" value="Google搜索"/></body>
</html>
另外你最好改下这个代码，不然识别不了 function selectOnChange() {
                 var province = document.getElementById("Select1");
                 var pindex = province.selectedIndex;
                 var pValue = province.options[pindex].value;
                 if (pValue == 0) {
                     document.getElementById("g").value = "Google  搜索";
                     document.getElementById("g").onclick = "javascript:googlesearch()";
                 } else if (pValue == 1) {
                     document.getElementById("g").value = "百度一下";
                     document.getElementById("g").onclick = "javascript:baiduesearch()";
                 }
             }