// TOGGLE AN IMAGE SOURCE BETWEEN TWO IMAGES
function toggleImage(id,image1,image2) {
    // IMAGE1 CURRENT
    if (document.getElementById(id).src == image1) {
        // SET SRC TO IMAGE2
        document.getElementById(id).src = image2;
    // IMAGE2 CURRENT
    } else {
        // SET SRC TO IMAGE1
        document.getElementById(id).src = image1;
    }        
}