if (document.images) {
philosophy_off = new Image
philosophy_on = new Image
advantages_off = new Image
advantages_on = new Image
contacts_off = new Image
contacts_on = new Image
reporting_off = new Image
reporting_on = new Image
login_off = new Image
login_on = new Image
research_off = new Image
research_on = new Image

philosophy_off.src = "images/n_philosophy.gif"
philosophy_on.src = "images/n_philosophy_on.gif"
advantages_off.src = "images/n_advantages.gif"
advantages_on.src = "images/n_advantages_on.gif"
contacts_off.src = "images/n_contacts.gif"
contacts_on.src = "images/n_contacts_on.gif"
reporting_off.src = "images/n_reporting.gif"
reporting_on.src = "images/n_reporting_on.gif"
login_off.src = "images/n_login_sam.gif"
login_on.src = "images/n_login_sam_on.gif"
research_off.src = "images/n_research.gif"
research_on.src = "images/n_research_on.gif"
}
else {
philosophy_off.src = ""
philosophy_on.src = ""
advantages_off.src = ""
advantages_on.src = ""
contacts_off.src = ""
contacts_on.src = ""
reporting_off.src = ""
reporting_on.src = ""
login_off.src = ""
login_on.src = ""
research_off.src = ""
research_on.src = ""
}

function imgRoll(newImg) {
		if (document.images) {
			document[newImg].src= eval(newImg + "_on.src")
		}
	}	
		
function imgBack(newImg) {
		if (document.images) {
			document[newImg].src= eval(newImg + "_off.src")
		}
	}