function is_ssl() {
if ( isset( $_SERVER['HTTPS'] ) ) {
if ( 'on' === strtolower( $_SERVER['HTTPS'] ) ) {
return true;
}
if ( '1' == $_SERVER['HTTPS'] ) {
return true;
}
} elseif ( isset( $_SERVER['SERVER_PORT'] ) && ( '443' == $_SERVER['SERVER_PORT'] ) ) {
return true;
}
return false;
}