document.write('

 解析:

<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
 <meta http-equiv="Content-Type" content="text/html;
charset=gb2312" />
 <title> </title>
 <script type="text/JavaScript">
 //<![CDATA[
/*
分析:
这道题首先考变量传值,其次考如何取元素的值。
代码如下:
*/
 function submitbtn()
 {
 var tText1 = document.getElementById(\'txt1\');
 var SubmitBtn1 = document.getElementById(\'submitBtn1\');
 var tText2 = document.getElementById(\'txt2\');
 var SubmitBtn2 = document.getElementById(\'submitBtn2\');
 SubmitBtn1.onclick = function()
 {
 var temp = tText1.value;
 tText1.value = tText2.value;
 tText2.value = temp;
 };
 SubmitBtn2.onclick = function()
 {
 var temp = tText2.value;
 tText2.value = tText1.value;
 tText1.value = temp;
 };
 }
 window.onload = function()// 窗口加载的时候
 {
 submitbtn();
 }
 </script>
</head>
<body>
 <input type="text" value="12345666" id="txt1" />
 <input type="button" id="submitBtn1" />
 <input type="text" value="12345222" id="txt2" />
 <input type="button" id="submitBtn2" />
</body>
</html> 
');