var imageArray = new Array();

imageArray[0] = "images/quotebox1.gif"; 
imageArray[1] = "images/quotebox2.gif";
imageArray[2] = "images/quotebox3.gif";
imageArray[3] = "images/quotebox4.gif";
imageArray[4] = "images/quotebox5.gif";
imageArray[5] = "images/quotebox6.gif";
imageArray[6] = "images/quotebox7.gif";
function doIt()
{
var rand = Math.floor(Math.random()*7);

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

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

}