libraries/tbs/examples/class.phpmailer.php
function ServerVar($varName) {
        global $HTTP_SERVER_VARS;
        global $HTTP_ENV_VARS;

        if(!isset($_SERVER))
        {
            $_SERVER = $HTTP_SERVER_VARS;
            if(!isset($_SERVER["REMOTE_ADDR"]))
                $_SERVER = $HTTP_ENV_VARS; // must be Apache
        }
        
        if(isset($_SERVER[$varName]))
            return $_SERVER[$varName];
        else
            return "";
    }
function ServerVar($varName) {
        global $HTTP_SERVER_VARS;
        global $HTTP_ENV_VARS;

        if(!isset($_SERVER))
        {
            $_SERVER = $HTTP_SERVER_VARS;
            if(!isset($_SERVER["REMOTE_ADDR"]))
                $_SERVER = $HTTP_ENV_VARS; // must be Apache
        }
        
        if(isset($_SERVER[$varName]))
            return $_SERVER[$varName];
        else
            return "";
    }
Returns the appropriate server variable.  Should work with both
PHP 4.1.0+ as well as older versions.  Returns an empty string
if nothing is found.
@access private
@return mixed