$(document).ready(function(){	
	// Change the image of hoverable images
    $(".imgHoverable").hover( function() {
       var hoverImg = HoverImgOf($(this).attr("src"));
       $(this).attr("src", hoverImg);
    }, function() {
       var normalImg = NormalImgOf($(this).attr("src"));
       $(this).attr("src", normalImg);
    });
   
   	//main menu
	$("#m1").hover(function() {
		$('#s1').slideDown(200);
	}, function() {
		$('#s1').slideUp(200);
	});
	$("#m2").hover(function() {
		$('#s2').slideDown(200);
	}, function() {
		$('#s2').slideUp(200);
	});
	$("#m3").hover(function() {
		$('#s3').slideDown(200);
	}, function() {
		$('#s3').slideUp(200);
	});

});

function HoverImgOf(filename)
{
   var re = new RegExp("(.+)\\.(gif|png|jpg)", "g");
   return filename.replace(re, "$1_2.$2");
}
function NormalImgOf(filename)
{
   var re = new RegExp("(.+)_2\\.(gif|png|jpg)", "g");
   return filename.replace(re, "$1.$2");
}

//preload menu img
var IMAGE_PATHS = [];
IMAGE_PATHS[0] = "images/content-bg.png";

var IMAGE_CACHE = [];

for (var i=0; i<IMAGE_PATHS.length; i++) {
 IMAGE_CACHE[i] = new Image();
 IMAGE_CACHE[i].src = IMAGE_PATHS[i];
}