jquery 处理密码输入框（input type="password" ） 模仿placeholder

<form method="post" action="">
<ul>
<li>
<span>邮箱</span>
<input type="text" name="email" value="请输入邮箱" onfocus="if(value == '请输入邮箱'){value =''}" onblur="if(value == ''){value ='请输入邮箱'}" >
</li>
<li>
<span>密码</span>
<input name="" type="text" value="密码" id="text" >
<input name="" type="password" style="display:none;" id="password">
</li>
<li>
<span>验证码</span>
<input type="text" name="code" class="code">
<img src="">
</li>
<li>
<span></span>
<label><input type="checkbox" checked="checked" name="check" class="checked"><i>记住密码</i></label>
<a href="" class="forget">忘记密码</a>
</li>
<li>
<span></span>
<a href="" class="login-btn">登录</a>
</li>
</ul>
</form>

<script type="text/javascript">
function _password(hid,pid){
var _hid = $("#"+hid);
var _pid = $("#"+pid);
_hid.focus(function(){
var _hval = $.trim($(this).val());
if(_hval != "密码") return;
$(this).css("display","none");
_pid.css("display","block").val("").focus();
});
_pid.blur(function(){
var _hval = $.trim($(this).val());
if(_hval != "") return;
$(this).css("display","none");
_hid.css("display","block").val("密码");
})
}
_password('text','password')
</script>