var num=0;

// format: src, header, text
imgArray = [  
 ['template/images/homeBG1.png', 'Text for Picture 1'],
 ['template/images/homeBG2.png', 'Text for Picture 2'],
 ['template/images/homeBG3.png', 'Text for Picture 3'],
 ['template/images/homeBG4.png', 'Text for Picture 4'],
];

function LimitNumber(value) {
  if (value < 0) { value = imgArray.length - 1; }
  var value = value % imgArray.length;
  return value; 
}
function slide(slide_num, homeInfo, Mylbl) {
  document.getElementById(homeInfo).style.backgroundImage="url("+imgArray[slide_num][0]+")";
  document.getElementById(Mylbl).innerHTML=imgArray[slide_num][1];
  document.getElementById(nav).className=imgArray[slide_num] + "selected";
}

var timedNum = 0;

function TimedImage() {
  timedNum++;
  timedNum = LimitNumber(timedNum);
  slide(timedNum,'homeInfo','mylbl');
}

var timedFunc = '';
function InitTimeInterval() {
  timedFunc = setInterval("TimedImage()", 15000);
}

function DisplaySlides(SNo) {
  clearInterval(timedFunc);
  slide(SNo,'homeInfo','mylbl');
}