jQuery.fn.darker = function(duration,css_array) {
	if(jQuery("#darker-div").length>0) return;
	jQuery("body").append('<div id="darker-div"></div>');
	jQuery("#darker-div")
		.css("z-index","99000")
		.css("position","absolute")
		.css("display","none")
		.css("top","0px")
		.css("left","0px")
		.css("right","0px")
		.css("margin","0px")
		.css("padding","0px")
		.css("width","100%")
		.css("height",darker_getPageSizeWithScroll()[0]+"px")
		.css("background-color","#000")
		.css("opacity",0.7);
	if(!(jQuery.browser.msie && jQuery.browser.version < 7))
		jQuery("#darker-div")
			.css("position","fixed")
			.css("height","100%");
	if(duration==null)
		jQuery("#darker-div").fadeIn("slow");
	else
		jQuery("#darker-div").fadeIn(duration);
	if(css_array!=null)
		jQuery("#darker-div").css(css_array);
}

jQuery.fn.closeDarker = function(duration){
	if(jQuery("#darker-div").length==0) return;
	if(duration==null) duration="slow";
	jQuery("#darker-div").fadeOut(duration,function(){
		jQuery("#darker-div").remove();
	});
};

function darker_getPageSizeWithScroll(){
		if (window.innerHeight && window.scrollMaxY) {// Firefox
			yWithScroll = window.innerHeight + window.scrollMaxY;
			xWithScroll = window.innerWidth + window.scrollMaxX;
		} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
			yWithScroll = document.body.scrollHeight;
			xWithScroll = document.body.scrollWidth;
		} else { // works in Explorer 6 Strict, Mozilla (not FF) and Safari
			yWithScroll = document.body.offsetHeight;
			xWithScroll = document.body.offsetWidth;
	  	}
		arrayPageSizeWithScroll = new Array(xWithScroll,yWithScroll);
		//alert( 'The height is ' + yWithScroll + ' and the width is ' + xWithScroll );
		return arrayPageSizeWithScroll;
	}