<form action="http://www.maultalk.com/ipb.html?act=Login&CODE=01&CookieDate=1" method="post">
<input type="text" size="20" name="UserName" onfocus="focus_username(this)" value="Имя пользователя"/>
<br/>
<input type="password" size="20" name="PassWord" onfocus="focus_password(this)" value="------"/>
<br/>
<input class="button" type="image" src="style_images/maulnet/login-button.gif"/>
</form>

<script type="text/javascript">
        $(document).ready(function() {
        
            $(document).mouseup(function() {
                $("#loginform").mouseup(function() {
                    return false
                });
                
                $("a.close").click(function(e){
                    e.preventDefault();
                    $("#loginform").hide();
                    $(".lock").fadeIn();
                });
                
                if ($("#loginform").is(":hidden"))
                {
                    $(".lock").fadeOut();
                } else {
                    $(".lock").fadeIn();
                }                
                $("#loginform").toggle();
            });
            
                   });
</script>

                if ($("#loginform").is(":hidden"))
                {
                    $(".lock").fadeOut();
                } else {
                    $(".lock").fadeIn();
                }

<div id="sign">Авторизация</div>

$("#sign").click(function(){
  if ($("#loginform").is(":hidden"))
  {
    $(".lock").fadeOut();
  } else {
    $(".lock").fadeIn();
  }
});