function changeCap(newCaption, fullImg, smallImg, smallImgWidth) {
    var caption = document.getElementById("photoCap").firstChild;
    var myText = newCaption;

    if(caption != null) caption.replaceData(0, 255, myText);

    document.getElementById('imgRef').href = fullImg;
    document.getElementById('imgSrc').src = 'http://postholer.com' + smallImg;
    document.getElementById('imgSrc').width = smallImgWidth;
}