У меня есть следующая форма HTML5: http://jsfiddle.net/nfgfP/
<form id="form" onsubmit="return(login())">
<input name="username" placeholder="Username" required />
<input name="pass" type="password" placeholder="Password" required/>
<br/>Remember me: <input type="checkbox" name="remember" value="true" /><br/>
<input type="submit" name="submit" value="Log In"/>