Fixed installAmination function

login-form.js

function installAnimation(inputElem, marginTopEnd, animationLength) {
    $(inputElem).bind('input', function() {
      var label = $(this).prev("label");
      var labelMarginTop = label.css('margin-top');
      label.stop();
      if ($(this).val().length > 0) {
        animateMarginTop(label, marginTopEnd, animationLength);
      } else if ($(this).val().length == 0) {
        animateMarginTop(label, "0px", animationLength);
      }
    });
}