[CODE]
<script>
<!--
function check()
{
 var x=document.form1;
 if(x.uid.value==""){
 alert("请输入帐号!");
 x.uid.focus();
 return false;}
 if(x.pwd.value==""){
 alert("请输入密码!");
 x.pwd.focus();
 return false;}
 if(x.pwd.value.length!=8){
 alert("密码必须为8位!");
 x.pwd.focus();
 return false;}
 alert("登录成功");
}
-->
</script>
<form name="form1" method="post" action="">
  <p>
    用户名:
      <input name="uid" type="text" id="uid">
</p>
  <p>密&nbsp;&nbsp;码:
    <input name="pwd" type="password" id="pwd">
</p>
  <p>
    <input type="submit" name="Submit" value="提交" onClick="return check()">
    <input type="reset" name="Submit2" value="重置">
  </p>
</form>[/CODE]