var ImgNum = 0;
var ImgLength = aryImages.length - 4;
//var delay = 3000;
var blnEnd
var lock = false;
var run;
function chgImg(direction) {
//  window.clearInterval();

 if (document.images) {
  ImgNum = ImgNum + direction;

  if (ImgNum > ImgLength) {
   ImgNum = 0
  }
  if (ImgNum < 0) {
   ImgNum = ImgLength;
  }

  document.slideshow1.src = aryImages[ImgNum];
  document.slideshow2.src = aryImages[ImgNum + 1];
  document.slideshow3.src = aryImages[ImgNum + 2];
  document.slideshow4.src = aryImages[ImgNum + 3];
  
 }
}

function auto() {
 if (lock == true) {
  lock = false;
  window.clearInterval(run);
 }
 else if (lock == false) {
  lock = true;
  run = setInterval("chgImg(1)", delay);
 }
}