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);

?>