if (document.images) {

nav_home_on = new Image();
nav_home_on.src = "../images/nav_home_on.gif";
nav_home_off = new Image();
nav_home_off.src = "../images/nav_home_off.gif";

nav_projects_on = new Image();
nav_projects_on.src = "../images/nav_projects_on.gif";
nav_projects_off = new Image();
nav_projects_off.src = "../images/nav_projects_off.gif";

nav_about_on = new Image();
nav_about_on.src = "../images/nav_about_on.gif";
nav_about_off = new Image();
nav_about_off.src = "../images/nav_about_off.gif";

nav_contact_on = new Image();
nav_contact_on.src = "../images/nav_contact_on.gif";
nav_contact_off = new Image();
nav_contact_off.src = "../images/nav_contact_off.gif";




}
function turnOn(imgName) {
        if (document.images) {
        	document[imgName].src = eval(imgName + "_on.src");
        }
}
function turnOff(imgName) {
        if (document.images) {
        	document[imgName].src = eval(imgName + "_off.src");
        }
}