Get Actual IP Address with PHP

/**
 * More reliable function to acquire actual user IP address
 * @access public
 * @param none
 * @return string
 */
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;
}