function changePhoto(url) {
    lastUrl = url;
    document.getElementById('M_CPI_ImgPhoto').src = url;

    return true;
}

var lastUrl;

function showPhoto(url) {
    lastUrl = document.getElementById('M_CPI_ImgPhoto').src;
    document.getElementById('M_CPI_ImgPhoto').src = url;
}

function hidePhoto(url) {
    document.getElementById('M_CPI_ImgPhoto').src = lastUrl;
}