code :
html>
<head>
<title>hello iframe reload</title>
</head>
<mce:script language="JavaScript"><!--
function change()
{
var url="http://www.baidu.com/s?wd=";
url += document.getElementById("name_input").value; //append parameter to url
document.getElementById("iframe_baidu").src=encodeURI(url); //don't forget encode url
}
// --></mce:script>
<body>
<form>
<input name="name" id="name_input" type="text">
<input type="button" οnclick="change()" value="change"> <!--regist function -->
</form>
<iframe id="iframe_baidu" width="100%" height="100%"></iframe>
</body>
</html>