var numimg;
var addbegin = "unset";
var addend = ".jpg";

function randimg()
{
  if (addbegin != "unset")
  {
    num = (Math.random() * 8) + 1
    num = parseInt(num)

    if (num > numimg) { num = numimg; }
    if (num < 1) { num = 1 }
    numstr = num + "";
    numimgstr = numimg + "";

    document.imgspin.src = addbegin + numstr + addend;
  }
}