Changing password from squirrelmail

hi,

I had configured openldap 2.3 in RHEL 5 operating system,

and my squirrel mail is running in RHEL 4.

I had integrated these two for address book synchronization.

Its working fine .In my squirrelmail options i had change password option.

I can able to chang the password by giving the old password and typing new password.

SO that it will automatically changed in openldap database also for a particular user.

But when am trying to change the password am getting error,

"Your login account was not found in the LDAP database, cannot change password!"