how to link a single login page to user and admin?

Question

hi, i need a help that how to  set a query for a login page.

i.e..,i have two databases user and admin.

       two panels[User and Admin]

        A single Login Page.

      How to give a connnection Or query to these two panels using a single login page?

    (i)  If user enters his credentilas he has to enter into the user panel.

     (ii) If Admin enters his credentilas he has to enter into his admin panel.

Here the image iam posting,that u can understand.