var imgSrc = new Array();
var count = 0;
var t;

imgSrc[0] = "img/trust.png";
imgSrc[1] = "img/bankruptcy.jpg";
imgSrc[2] = "img/shortsale.jpg";
imgSrc[3] = "img/debtsettlement.jpg";

function changeImagesAfterPeriod()
{
   document.getElementById('imageToChange').src = imgSrc[count % 4];
   setTimeout("changeImagesAfterPeriod()", 5000);
   count++;
}