if (document.images) {
	nav1on = new Image();	nav1off = new Image();
	nav2on = new Image();	nav2off = new Image();
	nav3on = new Image();	nav3off = new Image();
	nav4on = new Image();	nav4off = new Image();
	nav5on = new Image();	nav5off = new Image();
	nav6on = new Image();	nav6off = new Image();
	
	nav1on.src = "images/nav/mxdc2005_o.gif";		nav1off.src = "images/nav/mxdc2005_n.gif";
	nav2on.src = "images/nav/paper_o.gif";			nav2off.src = "images/nav/paper_n.gif";
	nav3on.src = "images/nav/papers_o.gif";			nav3off.src = "images/nav/papers_n.gif";
	nav4on.src = "images/nav/registration_o.gif";	nav4off.src = "images/nav/registration_n.gif";
	nav5on.src = "images/nav/program_o.gif";		nav5off.src = "images/nav/program_n.gif";
	nav6on.src = "images/nav/questions_o.gif";		nav6off.src = "images/nav/questions_n.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");
	}
}