function chooseImage() {
	if (!document.getElementsByTagName) return false;  //tests the browser's js support
	if (!document.getElementById) return false; //tests the browser's js support
	if (!document.getElementById("homeImage")) return false;
	var imageNum = (Math.floor(Math.random()*5) +1);
	var imagePlace = document.getElementById("homeImage");
	var allImages = imagePlace.getElementsByTagName("img");
	var image = allImages[0];
	var newSource = 'images/people/photogroup'+imageNum+'.jpg';
	image.setAttribute("src",newSource);
}

function prepareLoad() {
	simplePreload( 'images/people/photogroup1.jpg', 'images/people/photogroup2.jpg', 'images/people/photogroup3.jpg'  );
}

function simplePreload() {
	var args = simplePreload.arguments;
	document.imageArray = new Array( args.length );
	for(var i = 0; i < args.length; i++ ) {
		document.imageArray[i] = new Image;
		document.imageArray[i].src = args[i];
	}
}

function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}

addLoadEvent(prepareLoad);
addLoadEvent(chooseImage);