var image1 = new Image();
image1.src = "Images/home.png";
var image2 = new Image();
image2.src = "Images/home1.png";

var image3 = new Image();
image3.src = "Images/people.png";
var image4 = new Image();
image4.src = "Images/people1.png";

var image5 = new Image();
image5.src = "Images/research.png";
var image6 = new Image();
image6.src = "research1.png";

var image7 = new Image();
image7.src = "Images/publications.png";
var image8 = new Image();
image8.src = "Images/publications1.png";

var image9 = new Image();
image9.src = "Images/news.png";
var image10 = new Image();
image10.src = "Images/news1.png";


var image11 = new Image();
image11.src = "Images/facilities.png";
var image12 = new Image();
image12.src = "Images/facilities1.png";

var image13 = new Image();
image13.src = "Images/awards.png";
var image14 = new Image();
image14.src = "Images/awards1.png";

var image15 = new Image();
image15.src = "Images/contact.png";
var image16 = new Image();
image16.src = "Images/contact1.png";

function roll_over(img_name, img_src)
   {
   document[img_name].src = img_src;
   }