function imageGallerySwap(galleryID, total, dir) {
	var imageImage = document.getElementById(galleryID + '_image') ;
	var imageCredit = document.getElementById(galleryID + '_credit') ;
	var imageCaption = document.getElementById(galleryID + '_caption') ;
	var currentImage = document.getElementById(galleryID + '_current') ;
	
	var x = parseInt(currentImage.value) ;
	var photo = 0 ;
	if ( dir == "next" ) {
		photo = x + 1 ;
	} else {
		photo = x - 1 ;
	}

	var thisImage = document.getElementById(galleryID + '_image_' + photo).value ;
	var thisCredit = document.getElementById(galleryID + '_credit_' + photo).value ;
	var thisCaption = document.getElementById(galleryID + '_caption_' + photo).value ;
	var thisWidth = document.getElementById(galleryID + '_width_' + photo).value ;
	var thisHeight = document.getElementById(galleryID + '_height_' + photo).value ;
	var thisFull = document.getElementById(galleryID + '_full_' + photo).value ;

	if ( thisCredit == "" ) {
		thisCredit = " " ;
	} else {
		thisCredit = "photo by " + thisCredit ;
	}
	if ( thisCaption == "" || !thisCaption ) thisCaption = " " ;

	imageImage.innerHTML = "<img src=\"" + thisImage + "\" style=\"border: solid 1px #ccc;\" alt=\"\"/>" ;
	imageCredit.innerHTML = thisCredit ;
	imageCaption.innerHTML = thisCaption ;

	var prevOn = document.getElementById(galleryID + '_prev_on') ;
	var prevOff = document.getElementById(galleryID + '_prev_off') ;
	var nextOn = document.getElementById(galleryID + '_next_on') ;
	var nextOff = document.getElementById(galleryID + '_next_off') ;

	if ( photo + 1 == total ) {
		prevOn.style.display = "" ;
		prevOff.style.display = "none" ;
		nextOn.style.display = "none" ;
		nextOff.style.display = "" ;
	} else if ( photo == 0 ) {
		prevOn.style.display = "none" ;
		prevOff.style.display = "" ;
		nextOn.style.display = "" ;
		nextOff.style.display = "none" ;
	} else {
		prevOn.style.display = "" ;
		prevOff.style.display = "none" ;
		nextOn.style.display = "" ;
		nextOff.style.display = "none" ;
	}

	currentImage.value = photo ;

}