Is this string conversion Class A big use?

convert | string PHP code:--------------------------------------------------------------------------------
?
/**
* String Conversion class
* Author: Michael Young
* Date: 2002-4-21
* E-mail:windring@yeah.net
* All rights reserved
*/
Class extendstring{

var $keyWord = "ilovechenyingmm.";

Get password
function GetPassword () {
if (file_exists ("Admin.ini") ==1) {
$file =fopen ("Admin.ini", "R");
Fseek ($file, 31);
$buffer =fgets ($file, 4096);
Fclose ($file);
return $buffer;
return $this->decrypt ($buffer); Decrypt
}else
return "Filenoexist";
}

Set Password
function SetPassword ($password) {
if (file_exists ("Admin.ini") ==1) {
$file =fopen ("Admin.ini", "w");
$WSTR = "[Admin password]\nadminpassword=". $this->encrypt ($password);
$wStr. = "\n\n# do not change the file arbitrarily, otherwise it will cause the system to not function properly";
$result =fwrite ($file, $WSTR);
Fclose ($file);
return $result;
}else
return 0;
}

Encryption
function Encrypt ($password) {
$keyWord = "ilovechenyingmm."; $i =strlen ($password);
if ($i <16) {
For ($j =0 $j <16-i; $j + +)
$password = $password. " ";
}
$nostr = $password;
for ($j =0; $j <strlen ($password); $j + +) {
$c 1=substr ($password, $j, 1);
$c =substr ($keyWord, $j, 1);
$c 2= (Ord ($c)) ^ (Ord ($c 1));
if (strlen ($c 2) <=1)
$c 2=. $c 2;
if (strlen ($c 2) ==2)
$c 2= "0". $c 2;
$s 1.= $c 2;
}
return $s 1;
}

Decrypt
function Decrypt ($password) {
$keyWord = "ilovechenyingmm.";
$i =strlen ($password);
$s 1 = "";
$stemp = "";
For ($j =0 $j < $i/3; $j + +) {
$stemp =substr ($password, $j *3,3);
$c =substr ($keyWord, $j, 1);
$c 1=CHR ((Ord ($c)) ^ $stemp);
$s 1.= $c 1;
}
Return trim ($s 1);
}
}
?>