function centeredWindow(height, width) {
    var top    = (screen.availHeight - height) / 2;
    var left   = (screen.availWidth - width) / 2;
    return "height="+height+",width="+width+",top="+top+",left="+left+",toolbar=0,scrollbars=2,resizable=no";
}

function printable(url) {
    var height = 700;
    var width  = 800;
    window.open(url,'',centeredWindow(height, width));
}

function printable_wide(url) {
    var height = 700;
    var width  = 900;
    window.open(url,'',centeredWindow(height, width));
}