jQuery: show/hide placeholder text in form inputs on hover

jq-show-hide-placeholder.js

$.fn.showHidePlaceholder = function(defaultValue) {
  $(this).each(function() {
    var $element = $(this);

    if($element[0].tagName.toLowerCase() == 'select') {
      $selectedOption = $element.children('option:selected');
        if($selectedOption.text() == defaultValue || $selectedOption.val() == defaultValue) {
          $element.addClass('placeholder');
      }

      $element.on('change', function() {
        $selectedOption = $element.children('option:selected');
        if($selectedOption.text() == defaultValue || $selectedOption.val() == defaultValue) {
          $element.addClass('placeholder');
        } else {
          $element.removeClass('placeholder');
        }

      });
    }
    else {
      if($element.val() == defaultValue)  {
        $element.addClass('placeholder');
      }
      $element.on('focus', function() {
        if($element.val() == defaultValue) {
          $element.val('').removeClass('placeholder');
        }
      });
      $element.on('blur', function() {
        if($element.val() == '') {
          $element.val(defaultValue).addClass('placeholder');
        }
      });
    }
  });

  return $(this);
}