//@author Alexander Farkas | v. 1.22
(function($){
if(!document.defaultView||!document.defaultView.getComputedStyle){
	var oldCurCSS=$.curCSS;
	$.curCSS=function(elem,name,force){
		if(name==='background-position'){name='backgroundPosition';}
		if(name!=='backgroundPosition'||!elem.currentStyle||elem.currentStyle[name]){return oldCurCSS.apply(this,arguments);}
		var style=elem.style;
		if(!force&&style&&style[name]){return style[name];}
		return oldCurCSS(elem,'backgroundPositionX',force)+' '+oldCurCSS(elem,'backgroundPositionY',force);
	};
}
var oldAnim=$.fn.animate;
$.fn.animate=function(prop){
	if('background-position' in prop){
		prop.backgroundPosition=prop['background-position'];
		delete prop['background-position'];
	}
	if('backgroundPosition' in prop){prop.backgroundPosition='('+ prop.backgroundPosition;}
	return oldAnim.apply(this,arguments);
};
function toArray(strg){
	strg=strg.replace(/left|top/g,'0px');
	strg=strg.replace(/right|bottom/g,'100%');
	strg=strg.replace(/([0-9\.]+)(\s|\)|$)/g,"$1px$2");
	var res=strg.match(/(-?[0-9\.]+)(px|\%|em|pt)\s(-?[0-9\.]+)(px|\%|em|pt)/);
	return [parseFloat(res[1],10),res[2],parseFloat(res[3],10),res[4]];
}
$.fx.step. backgroundPosition=function(fx){
	if(!fx.bgPosReady){
		var start=$.curCSS(fx.elem,'backgroundPosition');
		if(!start){start='0px 0px';}
		start=toArray(start);
		fx.start=[start[0],start[2]];
		var end=toArray(fx.end);
		fx.end=[end[0],end[2]];
		fx.unit=[end[1],end[3]];
		fx.bgPosReady=true;
	}
	var nowPosX=[];
	nowPosX[0]=((fx.end[0]-fx.start[0])*fx.pos)+fx.start[0]+fx.unit[0];
	nowPosX[1]=((fx.end[1]-fx.start[1])*fx.pos)+fx.start[1]+fx.unit[1];           
	fx.elem.style.backgroundPosition=nowPosX[0]+' '+nowPosX[1];
};
})(jQuery);