//additional properties for jQuery object
$(document).ready(function(){
   //align element in the middle of the screen
   $.fn.alignCenter = function() {
      //get margin left
	  var thh=$(this).height()
//alert('1  '+thh)
      if(thh<=100) thh=300;
//alert('3  '+thh)
      var marginLeft = Math.max(40, parseInt($(window).width()/2 - $(this).width()/2  + $(window).scrollLeft())) + 'px';
//      var marginTop = Math.max(40, parseInt($(window).height()/2 - $(this).height()/2)) + 'px';

//      var marginTop = Math.max(40, parseInt($(window).height()/2 - thh/2)) + 'px';
		
		var marginTop = Math.max(40, parseInt($(window).height()/2 - thh/2 + $(window).scrollTop())) + 'px';

		if(thh>400) thh=400;
		thh+='px';
//alert(thh)



	  //return updated element
//	  return $(this).css({'margin-left':marginLeft, 'margin-top':marginTop, 'height':thh});
	  return $(this).css({'margin-left':marginLeft, 'margin-top':marginTop});
   };

});