I have a database called cohort in sql server 2008 r2 express with a table called school with the following fields; schoolname,schoolcode,zone,district,division.I also have vb 2010 form with five comboboxes.Now my question is how can i link comboxbox1 to table field schoolname,combobox2 to schoolcode,combobox3 to zone,combobox4 to district,combobox5 to division. And how to apply filter in combobox.For example if i select a particular division in combobox the next combobox for zone should only display zones for that particular division etc. I have tried to add data source to my vb application but cannot access it. Is there any coding that can substitute data objects on the form. I have managed to write a connection string for the database.