Login for coding..

iam new to c # ..and recently trying to develop[ a small project to myself . since 5 days iam trying to develop a login for which contains USERNAME (textbox),PASSWORD (textbox),DESIGNATION(combobox).. now the user wil be directed to different form basing on the user name password and selected designation .. form the list (PRINCIPAL,HEADMASTER,ACCOUNTANT).. IF THE DETAILS ARE VERIFIED FROM THE DATABASE THEN HE IS DIRECTED TO PRINCIPAL FORM OR HEADMASTER FORM OR ACCOUNTANT FORM .. iam using sqlserver 2005, and VS2008 IDE ...