var theImages = new Array() 
		theImages[0] = 'images/hp_main_a.jpg'
		theImages[1] = 'images/hp_main_b.jpg'
		theImages[2] = 'images/hp_main_c.jpg'
		theImages[3] = 'images/hp_main_d.jpg'
		var j = 0
		var p = theImages.length;
		var preBuffer = new Array()
		for (i = 0; i < p; i++){
   		preBuffer[i] = new Image()
   		preBuffer[i].src = theImages[i]
		}
		var whichImage = Math.round(Math.random()*(p-1));
		function showImage(){
		document.write('<img src="'+theImages[whichImage]+'" height="262" width="510" border="0">');
		}