function swapPhoto(photoSRC,theCaption) {

if (document.getElementById("caption")) {

	var theImage = document.getElementById("mainPhoto");
	var displayedCaption = document.getElementById("caption");
	var imgFolder = "assets/";
	displayedCaption.firstChild.nodeValue = theCaption;
	theImage.setAttribute("src", imgFolder+photoSRC);

    }
  }