//Input username/password validation jQuery
$('input[name=username]').change(function() {            <----------your input element name
          var user = $('#username').val();
          if(user.length < 5 ) {
              $("#errorUser").removeClass("hidden");      <----------your message element id ex. <p id=errormessage>input 5 </p>
          } else
              $("#errorUser").addClass("hidden");			<----------your message element id
      });
      $('input[name=password]').change(function() {        <----------your input element name
          var pass = $('#password').val();
          if(pass.length < 5 ) {
              $("#errorPassword").removeClass("hidden");		<----------your message element id
          } else
              $("#errorPassword").addClass("hidden");			<----------your message element id
      });