<script type="text/javascript" language="javascript">
var username = null;
var password = null;
//获取文本框
onload = function()
{
username = document.getElementById("txtUserName");
password = document.getElementById("txtPassWord");
}
//清空文本框
function clearTxt()
{
username.value = "";
password.value = "";
username.focus();
// document.getElementById('txtUserName').value="";
// document.getElementById('txtPassWord').value="