function ROverImg(classname, prefix, time){
	
	if(prefix == ''){
		prefix = '_f2';
	}
	
	$("img").each(function(){

		var src = $(this).attr("src");
		
		if($(this).hasClass(classname) && src.indexOf(prefix + ".") == -1){
			
			var size = src.length;
			var over = src.substring(0, size - 4) + prefix + src.substring(size - 4, size);

			var par = $(this).parent();
			par.css("display", "block").css("position", "relative");
			
			var clone = $(this).clone();
			clone.attr("src", over).attr("class", "clone");
			clone.css("position", "absolute").css("top", "0").css("left", "0");
			
			$(this).after(clone);
			clone.hide();
			
			par.hover(
			    function(){
			    	$(this).find('.clone').fadeIn(time);
			    },
			    function(){
			    	$(this).find('.clone').fadeOut(time);
			    }
			); 
		}
	});
}