$(function() {
$("#submit_login").click(function() {
var username = $("#email").val();
var password = $("#password").val();
var dataString = username + password;

if(username && password != '')
{
$.ajax({
type: "POST",
url: "/design/index.php",
data: dataString,
success: function(){
alert("Data sent!");
}
});
}
return false;
});
});

<form action="" method="post">
  <input type="text" name="uname" id="email" class="input_login_2" value="e-mail adress" onclick="clickclear(this, 'e-mail adress')"
  onblur="clickrecall(this,'e-mail adress')">
<br>
  <input type="password" name="pword" id="password" class="input_login" value="password" onclick="clickclear(this, 'password')"
  onblur="clickrecall(this,'password')">
<br>
  <input type="submit" name="submit_login" class="input_submit" value="login!" id="submit_login">
</form>