if (document.images) {
image0 = new Image(); image0.src = "raw0.jpg";
image1 = new Image(); image1.src = "raw1.jpg";
image2 = new Image(); image2.src = "raw2.jpg";
image3 = new Image(); image3.src = "raw3.jpg";
image4 = new Image(); image4.src = "raw4.jpg";
}
picNum = 1
maxImages = 4;

function chgPic()
{ 
document.img.src = "raw" + picNum + ".jpg";
picNum == maxImages ? picNum = 0 : picNum ++;
}