if(document.images){  
//  nav OFF state
n_home_off = new Image(126, 30); n_home_off.src = "images/n_home.gif";   
n_articles_off = new Image(126, 30); n_articles_off.src = "images/n_articles.gif";   
n_resources_off = new Image(126, 30); n_resources_off.src = "images/n_resources.gif";   
//  nav ON state
n_home_on = new Image(126, 30); n_home_on.src = "images/n_home_o.gif";   
n_articles_on = new Image(93, 16); n_articles_on.src = "images/n_articles_o.gif";   
n_resources_on = new Image(126, 30); n_resources_on.src = "images/n_resources_o.gif";   
}
function imgOn(imgName) {
        if (document.images) {
		document[imgName].src = eval(imgName + "_on.src");
        }
}
function imgOff(imgName) {
        if (document.images) {
		document[imgName].src = eval(imgName + "_off.src");
        }
}