各位大侠来看看 小弟求教

<script language="javascript">
function yzm(){
var str=new String();
var m=1;
var n=36;
var a=new Array("0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z");
for(i=0;i<4;i++){
var z=parseInt(Math.random()*(n-m)+m);
str=str+a[z];
}
         document.write(str);
}function huoqu(){
var lab=document.getElementById("lab");
var labvalue=lab.firstChild.nodeValue;
alert(labvalue);

}</script><body>
<label id="lab"><script language="javascript">yzm();</script></label>
<input type="button" onclick="huoqu()" value="获取验证码"> 
</body>我的意图：想把函数中的随机数字显示在标签<label>中作为text值，然后通过单击按钮获取标签<label>的文本值。
 求教大家 有什么方法啊？   我的这个方式明显不行，单击按钮获取不到标签中的文本值。求教大家了！！！！！

解决方案 »

  1.   


    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
    <title>无标题文档</title>
    <script language="javascript">
    function yzm(){
        var str=new String();
        var m=1;
        var n=36;
        var a=new Array("0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z");
        for(i=0;i<4;i++){
        var z=parseInt(Math.random()*(n-m)+m);
        str=str+a[z];
        }
    var lab=document.getElementById("lab");
    lab.innerHTML = str;
             //document.write(str);
    }function huoqu(){
        var lab=document.getElementById("lab");
        var labvalue=lab.innerHTML;
        alert(labvalue);
        
    }</script><body>
    <label id="lab"><script language="javascript">yzm();</script></label>
    <input type="button" onclick="huoqu()" value="获取验证码"> 
    </body></html>
      

  2.   

    function yzm(){
        var str=new String();
        var m=1;
        var n=36;
        var a=new Array("0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z");
        for(i=0;i<4;i++){
        var z=parseInt(Math.random()*(n-m)+m);
        str=str+a[z];
        }
        return str;
    }
    function huoqu(){
        var lab=document.getElementById("lab");
        lab.innerText=yzm();
        var labvalue=lab.innerText;
        alert(labvalue);
        
    }
      

  3.   

    yzm()通过body的onload事件调用下看看
      

  4.   

    唉，我郁闷，脑壳昏了，没想到用DOM来插入文本，MuBeiBei 代码点醒梦中人！