function RandomImage(images,w,h)
{
    var j = 0;
    var p = images.length;
    var preBuffer = new Array();
    for (i = 0; i < p; i++)
    {
        preBuffer[i] = new Image();
        preBuffer[i].src = images[i];
    }
    var whichImage = Math.round(Math.random()*(p-1));
    document.write('<img src="'+ images[whichImage] +'">');   
}