js验证页面两个密码是否一致

<script language="javascript">
function comparePwd()
{
var pwd1=document.forms[0].Userpwd.value;
var pwd2=document.forms[0].chkpwd.value;
if(pwd2!=pwd1)
{
alert("两次输入的密码不一致");
document.forms[0].Userpwd.value="";
document.forms[0].chkpwd.value="";
document.forms[0].Userpwd.focus();
}
}
</script>