var image1 = new Image();
image1.src = "images/section1.png";
var image2 = new Image();
image2.src = "images/section1_over.png";
var image3 = new Image();
image3.src = "images/section2.png";
var image4 = new Image();
image4.src = "images/section2_over.png";
var image5 = new Image();
image5.src = "images/section3.png";
var image6 = new Image();
image6.src = "images/section3_over.png";
var image4 = new Image();
image4.src = "images/main/1_liquiforce.png";
var image5 = new Image();
image5.src = "images/main/2_services.png";
var image6 = new Image();
image6.src = "images/main/3_testimonials.png";

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