img1 = new Image();
img1.src = "img/logo1.gif";
img2 = new Image();
img2.src = "img/logo2.gif";

function domSwap(){
theImg=document.getElementById("myImage");
theImg.setAttribute("src","img/logo2.gif");
}

function domSwapBack(){
theImg=document.getElementById("myImage");
theImg.setAttribute("src","img/logo1.gif");
}