is there anyway to hide my rows in section in tableview? and when i click section header row should expand to view?

i build a tableview with data imported from database. data is contacts in various sections which are alphabets. now i want to hide the number of rows in section in tableview. when i click the section title that means 'A' (alphabet) those row in that section should be shown to user (Alex, Aron, Alvin, etc..contacts in A-section). Can anybody tell me how to do this...ut i've already done some work like celleditingstyle for deleting a cell, alertview for deleting cell..i need quick response..plz..