<!-- Paste this code into an external JavaScript file named: nextPrevious.js  -->
  
  /* This script and many more are available free online at
  The JavaScript Source :: http://javascript.internet.com
  Created by: Solomon, the Sleuth :: http://www.freewebs.com/thesleuth/scripts/ */
  
  // List image names without extension
  var myImg= new Array(3)
    myImg[0]= "pix1";
    myImg[1]= "pix2";
    myImg[2]= "pix3";
    myImg[3]= "pix4";
  
  // Tell browser where to find the image
  myImgSrc = "/img";
  
  // Tell browser the type of file
  myImgEnd = ".jpg"
  
  var i = 0;
  
  // Create function to load image
  function loadImg(){
    document.imgSrc.src = myImgSrc + myImg[i] + myImgEnd;
  }
  
  // Create link function to switch image backward
  function prev(){
    if(i<1){
      var l = i
    } else {
      var l = i-=1;
    }
    document.imgSrc.src = myImgSrc + myImg[l] + myImgEnd;
  }
  
  // Create link function to switch image forward
  function next(){
    if(i>2){
      var l = i
    } else {
      var l = i+=1;
    }
    document.imgSrc.src = myImgSrc + myImg[l] + myImgEnd;
  }
  
  // Load function after page loads
  window.onload=loadImg;