var images = new Array();

images[0] = "images/guytonImg/g0.jpg";
images[1] = "images/guytonImg/g1.jpg";
images[2] = "images/guytonImg/g2.jpg"; 
images[3] = "images/guytonImg/g3.jpg";
images[4] = "images/guytonImg/g4.jpg";
images[5] = "images/guytonImg/g5.jpg";
images[6] = "images/guytonImg/g6.jpg";
images[7] = "images/guytonImg/g7.jpg";

function showImg() 
{
    var number = images.length;
    increment = Math.floor(Math.random() * number);
    var strTemp ='<img src="' + images[increment] + '" border="0">';    
    document.write(strTemp);   
}