arr = new Array(
["images/slideshow/slideshow1.jpg","Chess"],
["images/slideshow/slideshow2.jpg",""], 
["images/slideshow/slideshow3.jpg",""],
["images/slideshow/slideshow4.jpg",""],
["images/slideshow/slideshow5.jpg",""]

// no comma at the end of last index 
);
var lastImg="0"; 

function changeimg()
{   var randNum = getRand();  
document.getElementById("img").src = arr[randNum][0]; 
document.getElementById("link").href = arr[randNum][1]; 
document.getElementById("img").title = arr[randNum][2]; 
setTimeout('changeimg()',3000);  }  
function getRand () {   var rnum;   
var id=Math.round(Math.random()*(arr.length-1));   
rnum = id;   if (rnum==lastImg) { rnum = getRand(); }   
lastImg=rnum;   return rnum;  }