$time_marker = 0;
function mark_timer(){
    $time = microtime();
    $time = explode(' ', $time);
    $time = (float)$time[1] + (float)$time[0];
    $_SESSION["time_marker"] = $time;
}
function end_and_print_timer($caption = ""){
    $time = microtime();
    $time = explode(' ', $time);
    $time = (float)$time[1] + (float)$time[0];
    $finish = $time;

    $total_time = round(($finish - $_SESSION["time_marker"]), 4);

    if(!empty($caption)){
        echo "<br/>$caption";
    }
    echo $total_time . "secs";
}
function reset_timer(){
    $_SESSION["time_marker"] = 0;
}