
<!-- Paste this code into an external JavaScript file named: nextPrevious.js  -->

// List image names without extension
var myImg= new Array(3)
  myImg[0]= "photo1";
  myImg[1]= "photo2";
  myImg[2]= "photo3";
  myImg[3]= "photo4";
  myImg[4]= "photo5";
  myImg[5]= "photo6";  
  myImg[6]= "photo7";
  myImg[7]= "photo8";
  myImg[8]= "photo9";
  myImg[9]= "photo10";
  myImg[10]= "photo11";  
  myImg[11]= "photo12";
  myImg[12]= "photo13";
  myImg[13]= "photo14";
  myImg[14]= "photo15";
  myImg[15]= "photo16";  
  myImg[16]= "photo17";
  myImg[17]= "photo18";
  myImg[18]= "photo19";
  myImg[19]= "photo20";
  myImg[20]= "photo21";  
  myImg[21]= "photo22";
  myImg[22]= "photo23";
  myImg[23]= "photo24";
  myImg[24]= "photo25";
  myImg[25]= "photo26";  
  myImg[26]= "photo27";
  myImg[27]= "photo28";
  myImg[28]= "photo29";
  myImg[29]= "photo30";
  myImg[30]= "photo31";  
  myImg[31]= "photo32";
  myImg[32]= "photo33";
  myImg[33]= "photo34";
  myImg[34]= "photo35";
  myImg[35]= "photo36";  
  myImg[36]= "photo37";
  myImg[37]= "photo38";
  myImg[38]= "photo39";
  myImg[39]= "photo40";
  myImg[40]= "photo41";
  myImg[41]= "photo42";
  myImg[42]= "photo43";
  myImg[43]= "photo44";
  myImg[44]= "photo45";
  myImg[45]= "photo46";  
  myImg[46]= "photo47";
  myImg[47]= "photo48";
  myImg[48]= "photo49";
  myImg[49]= "photo50";
  myImg[50]= "photo51";

// Tell browser where to find the image
myImgSrc = "images/";

// 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>49){
    var l = i
  } else {
    var l = i+=1;
  }
  document.imgSrc.src = myImgSrc + myImg[l] + myImgEnd;
}

// Load function after page loads
window.onload=loadImg;