(function($){
  $.fn.dropShadow = function(options) {
    var options = $.extend({
      top: 1,
      left: 1,
      top_fix: 0,
      left_fix: 0,
      color: '#000000'
    }, options);


    this.not('.dropShadow').each(function() {
      var _marginTop = $(this).css('marginTop');
      _marginTop = _marginTop.substr(0, _marginTop.length-2)*1;
      var _marginLeft = $(this).css('marginLeft');
      _marginLeft = _marginLeft.substr(0, _marginLeft.length-2)*1;

      var _top = $(this).position().top + options.top_fix + _marginTop;
      var _left = $(this).position().left + options.left_fix + _marginLeft;

      $(this).clone().insertBefore(this).addClass('dropShadow').css({
        color: options.color,
        position: 'absolute',
        top: options.top+_top+'px',
        left: options.left+_left+'px'
      });

      $(this).css({
        position: 'absolute',
        top: _top+'px',
        left: _left+'px'
      });

      $(this).after('<div style="width:'+$(this).outerWidth(true)+'px;height:'+$(this).outerHeight(true)+'px" class="dropshadow_tmp"></div>');

      $('.dropshadow_tmp').css({
        padding: 0,
        margin: 0,
        border: 0,
        display: 'block',
        opacity: 0
      });
    });
  }
})(jQuery);