//The array which is going to hold the image information. Store the image info along with their correct path; I've omitted the path here as I've stored the images in the same folder where my web page resides.
var imageArray = new Array();

imageArray[0] = "1.jpg"; //You can replace these image file names with your own image names.
imageArray[1] = "2.jpg";
imageArray[2] = "3.jpg";
imageArray[3] = "4.jpg";
function doIt()
{
var rand = Math.floor(Math.random()*4); //Generating a random number between 0 and 3 here in your case you can replace 4 with 11 if you have 10 images

var imgPath = "<img src='"+imageArray[rand]+"' alt='.' border='0' align='absmiddle' />";

document.getElementById("image").innerHTML = imgPath;

}
doIt();