DataGrid view with combobox

Question

i have a form that created using C# 2010. in this there is a combo box called "cmbDept" and datagrid view name is "DataGrideView"   i just need to populate data from my SQL 2008 data base (HRM) table (NewEmp) according to selection is made by my combo box (cmbDept).
this combo box have values (All, Philips Division, Power Tool, Wipro).   my table have values (EmpID, Name, ContactNo, Post, Department)
you can click the attachment to see real look of my interface. 
Pls in advance...

Thanks to you for your commitment