mcrypt_encrypt help needed

Hello all. I am using the following function to encrypt a string: define('SALT', 'myvalueforsalthere'); function encrypt($text) {

    return trim(base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, SALT, $text, MCRYPT_MODE_ECB, mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND))));

} and then: $myval="hello"; $mayval= encrypt($myval); echo decrypt($myval); returns "hello".... great. But when my input string is more complicated I get unprintable characters out of the decyrpt side: $myval="var1=1&var2=2&var3=3"; The above when decrypted will spit out a string of unprintable characters. Is encrypt/decrypt choking on the "=" sign? I tried: $myval=htmlentities($myval); But it did not work. Any help is appreciated. Thanks, --Rick