create trigger to insert another entry in a table after creating a user

Hello,

I need to create trigger to insert another entry in a table after creating a user.

Suppose username is Aakash Dore    .Now I create user with username as adore (first letter of first name and last name)Now I need to add another entry in a table which would give full name of the user like a mapping with username and full name.

Please suggest how can we do this.

Best regards,

Vishal