var selected = '';
var preloadFlag = false;

function newImage(arg) {
    if (document.images) {
        rslt = new Image();
        rslt.src = arg;
        return rslt;
    }
}    

function changeImagesArray(array) {
    if (document.images && (preloadFlag == true)) {
	    for (var i=0; i<array.length; i+=2) {
		    document[array[i]].src = array[i+1];
	    }
    }
}

function changeImages() {
    changeImagesArray(changeImages.arguments);
}

function toggleImages() {
    for (var i=0; i<toggleImages.arguments.length; i+=2) {
	    if (selected == toggleImages.arguments[i])
		    {changeImagesArray(toggleImages.arguments[i+1]);}
    }
}

function preloadImages() {
    if (document.images) {
	    Home_Button_over = newImage("/images/v3/header/Home_Button-over.gif");
	    Menu_My_Account_over = newImage("/images/v3/header/Menu-My_Account_over.gif");
	    Menu_Course_Cat_over = newImage("/images/v3/header/Menu-Course_Cat_over.gif");
	    Menu_About_Us_over = newImage("/images/v3/header/Menu-About_Us_over.gif");
	    Menu_Links_over = newImage("/images/v3/header/Menu-Links_over.gif");
	    Menu_Help_over = newImage("/images/v3/header/Menu-Help_over.gif");
	    preloadFlag = true;
    }
}

$(document).ready(function() {
    preloadImages();
});