PHP Function to encode and decode string in PHP

Simple php function to encode and decode a string in php. This function uses simple base64_encode to encode the string.

function base64url_encode($mytext) {
    $base64 = base64_encode($mytext);
    $base64url = strtr($base64, '+/=', '-_,');
    return $base64url;
}

function base64url_decode($mytext) {
    $base64url = strtr($mytext, '-_,', '+/=');
    $base64 = base64_decode($base64url);
    return $base64;
}