Access denied for user ''@'localhost' to database 'questdebug

Hi,

Yesterday I downloaded and installed "Toad for mysql 6.3.0.642’.
My installation is under Trial Version license.
I’m using MySQL 5.5.20
After trying to debug a function, I received the following messages:

  1. MySQL Database Error: Access denied for user ‘’@‘localhost’ to database ‘questsoftware’
  2. MySQL Database Error: Access denied for user ‘’@‘localhost’ to database ‘questdebug’

I don’t know how to solve this issue.
I would be glad if anybody could help me in solving this issue.

Thank you in advance.