get Ip address in php

function getip() {
    if (isSet($_SERVER)) {
        if (isSet($_SERVER["HTTP_X_FORWARDED_FOR"])) {
            $realip = $_SERVER["HTTP_X_FORWARDED_FOR"];
        } elseif (isSet($_SERVER["HTTP_CLIENT_IP"])) {
            $realip = $_SERVER["HTTP_CLIENT_IP"];
        } else {
             $realip = $_SERVER["REMOTE_ADDR"];
        }
    } else {
         if ( getenv( 'HTTP_X_FORWARDED_FOR' ) ) {
              $realip = getenv( 'HTTP_X_FORWARDED_FOR' );
         } elseif ( getenv( 'HTTP_CLIENT_IP' ) ) {
              $realip = getenv( 'HTTP_CLIENT_IP' );
         } else {
              $realip = getenv( 'REMOTE_ADDR' );
         }
    }
    return $realip;
}