if (document.images)
{
	link1_on= new Image(150,30);
	link1_on.src="images/nav-home_over.png";
	link1_off= new Image(150,30);
	link1_off.src="images/nav-home.png";

	link2_on= new Image(150,30);
	link2_on.src="images/nav-mission_over.png";
	link2_off= new Image(150,30);
	link2_off.src="images/nav-mission.png";

	link3_on= new Image(150,30);
	link3_on.src="images/nav-research_over.png";
	link3_off= new Image(150,30);
	link3_off.src="images/nav-research.png";

	link4_on= new Image(150,30);
	link4_on.src="images/nav-publications_over.png";
	link4_off= new Image(150,30);
	link4_off.src="images/nav-publications.png";

	link5_on= new Image(150,30);
	link5_on.src="images/nav-faculty_over.png";
	link5_off= new Image(150,30);
	link5_off.src="images/nav-faculty.png";
	
	link6_on= new Image(150,30);
	link6_on.src="images/nav-students_over.png";
	link6_off= new Image(150,30);
	link6_off.src="images/nav-students.png";

	link7_on= new Image(150,30);
	link7_on.src="images/nav-contactdml_over.png";
	link7_off= new Image(150,30);
	link7_off.src="images/nav-contactdml.png";

	link8_on= new Image(150,30);
	link8_on.src="images/nav-videos_over.png";
	link8_off= new Image(150,30);
	link8_off.src="images/nav-videos.png";
}

function lightup(imgName)
{
	if (document.images)
	{
		imgOn=eval(imgName + "_on.src");
		document[imgName].src= imgOn;
	}
}

function turnoff(imgName)
{
	if (document.images)
	{
		imgOff=eval(imgName + "_off.src");
		document[imgName].src= imgOff;
	}
}