onfocus="if(this.value=='Логин') this.value='';" onblur="if(this.value=='') this.value='Логин';" value="Логин"

<input autofocus class="loginField" type="text" name="user" value="Логин" onclick="if(this.value=='Логин'){this.value=''}" onclick="if(this.value=='Логин'){this.value=''}" onblur="if(this.value==''){this.value='Логин'}" size="20" maxlength="50" tabindex="1"/>
<input class="loginField" type="text" name="password" size="20" value="Пароль" onfocus="if(this.value=='Пароль'){this.value='', this.type='password'}" ondblclick="if(this.type=='password'){this.type='text'}" onclick="if(this.type=='text'){this.type='password'}" onblur="if(this.value==''){this.type='text', this.value='Пароль'}" tabindex="2"/>

<ul id="logForm">
<li class="title">Авторизация</li>
<li class="input"><input id="log" name="" type="text" onkeyup="$(this).css('background','#fff')" onblur="if(this.value !==''){$(this).css('background','#fff')} else {$(this).css('background','none')}"><span>Логин</span></li>
<li class="input"><input id="log" name="" type="password" onkeyup="$(this).css('background','#fff')" onblur="if(this.value !==''){$(this).css('background','#fff')} else {$(this).css('background','none')}"><span>Пароль</span><a href="#">Забыл пароль</a></li>
<li class="button"><input type="button" value="Вход на сайт"></li>
<li class="options"><input id="rem" type="checkbox" checked="checked"> <label for="rem">Запомнить</label> | <a href="#">Регистрация</a></li>
</ul>

<style>
body {background: #f3f3f3}

ul#logForm{font:12px Tahoma, Geneva, sans-serif; color:#999; list-style:none; margin:0; background:#f8f8f8; padding:5px 10px; width:220px; box-shadow:0 1px 2px rgba(0,0,0,0.3); border-radius:0 0 2px 2px}

ul#logForm li{position:relative; padding:5px 0}

li.title{font-size:14px; font-weight:700; text-align:right}

li.title:first-letter{color:#62b841}

li.input{background:#fff; color:#ccc}

li.input input{color:#666; display:block; height:28px; line-height:28px; width:198px; padding:0 10px; border:1px solid #ccc; background:none; position:relative; z-index:2; box-shadow:inset 0 0 5px rgba(0,0,0,0.1)}

.input span{display:block; line-height:30px; color:#ccc; position:absolute; top:5px; left:0; z-index:1; height: 30px; padding:0 10px; background:#fff}

input:focus+span{display:none}

.input a{display:block; font-size:11px; color:#ccc; text-decoration:none; height:28px; line-height:28px; padding:0 5px; position:absolute; top:5px; right:0; z-index:3; background:#f8f8f8; border:1px solid #ccc; border-radius: 0 3px 3px 0}

.button input {font-weight:700; color:#fff; background:#62b841; cursor:pointer; border: 1px solid #090; height:30px; width:100%; text-shadow:0 1px 0 rgba(0,0,0,0.3); box-shadow:inset 0 1px 1px rgba(255,255,255,0.3)}

li.input, li.input input, .button input{border-radius:3px}   

.options{ height:20px; line-height:20px; text-align:center;}

.options label{cursor:pointer}

.options input {margin:0; vertical-align: text-bottom}

.options a {color:#62b841; text-decoration:none}
</style>