Hello meLady,

1. verify for null username (username cannot be null)
2. verify for null password (password cannot be null)
3. If we get a username and password, authenticate it wih PLSQL like SELECT password into vresult
from users where username=txtUsername;
IF(txtPassword = vresult) THEN
/*You are in*/
ELSE
/*You are not in*/
END IF;
4. This is all meLady. Yes, you can have ecrypted password stored in table
and encrypt the password given by user while verifying the password that
user enters. For this, the function used while encrypting the password
given for new user should be same as the decrypting function while
verifying at Login.

Sorry, for late respose as i was out of town, but bfr leaving i sent this solution which somehow couldn't submitted.

Enjoy coding.