var imageArray = new Array();

imageArray[0] = new Image();
imageArray[1] = new Image();
imageArray[2] = new Image();
imageArray[3] = new Image();
imageArray[4] = new Image();
imageArray[0].src = "process1si.jpg";
imageArray[1].src = "process2si.jpg";
imageArray[2].src = "process3si.jpg";
imageArray[3].src = "process4si.jpg";
imageArray[4].src = "process5si.jpg";

function imgSwap( img, index )
{
	document.images[img].src = imageArray[index].src;
}