生成sessionid和随机密码的例子

用这个可以来验证用户和生成随机密码--teaman
<?
//----------------------------------------------------
// Function GetSID()
//
// Parameters : $nSize number of caracters, default 24
// Return value : 24 caracters string
//
// Description : This function returns a random string
// of 24 caracters that can be used to identify users
// on your web site in a more secure way. You can also
// use this function to generate passwords.
//----------------------------------------------------
function GetSID ($nSize=24) {

        // Randomize   
        mt_srand ((double) microtime() * 1000000);   
        for ($i=1; $i<=$nSize; $i++) {   

            // if you wish to add numbers in your string,    
            // uncomment the two lines that are commented   
            // in the if statement   
            $nRandom = mt_rand(1,30);   
            if ($nRandom <= 10) {   
                // Uppercase letters   
                $sessionID .= chr(mt_rand(65,90));   
        //    } elseif ($nRandom <= 20) {   
        //        $sessionID .= mt_rand(0,9);   
            } else {   
                // Lowercase letters   
                $sessionID .= chr(mt_rand(97,122));   
            }   

        }           
        return $sessionID;   
    }   
    // Test the function    
    echo GetSID(16);   
?>