首先最简单的验证不能为空
<FORM id="loginForm" name="loginForm" onSubmit="return check()" action="login.do" method="post">
<div id="login2">
<div id="login5"><br />用户名 </div>
<div id="login6">
<INPUT class="input" tabIndex="1" type="text" maxLength="20" size="35" name="UName">
</div>
</div>
<div id="login3">
<div id="login5"><br />密 码 </div>
<div id="login6"><INPUT class="input" tabIndex="2" type="password" maxLength="20" size="40" name="UPass"></div>
</div>
<div id="login4">
<div id="login7"><br />
<INPUT class="btn" tabIndex="6" type="submit" value="登 录">
<INPUT class="btn" type="reset" value="重置">
</div>
</div>
</FORM>
<script language="javascript">
function check() {
if(document.loginForm.UName.value==""){
alert("用户名不能为空");return false;
}
if(document.loginForm.UPass.value==""){
alert("密码不能为空"); return false;
}
}
</script>