var rand1 = 0;
var useRand = 0;
images = new Array;
images[1] = new Image();
images[1].src = "images/headers/header1.jpg";
images[2] = new Image();
images[2].src = "images/headers/header2.jpg";
images[3] = new Image();
images[3].src = "images/headers/header3.jpg";
images[4] = new Image();
images[4].src = "images/headers/header4.jpg";
images[5] = new Image();
images[5].src = "images/headers/header5.jpg";
images[6] = new Image();
images[6].src = "images/headers/header6.jpg";
images[7] = new Image();
images[7].src = "images/headers/header7.jpg";

function swapPic() {
var imgnum = images.length - 1;
do {
var randnum = Math.random();
rand1 = Math.round((imgnum - 1) * randnum) + 1;
} while (rand1 == useRand);
useRand = rand1;
document.randimg.src = images[useRand].src;
}