Datagrid Sum Column and cutomization plz help

Hello


Dear i Want to make a datagrid having Five columns Using C#

one Date column with date time picker and other Amount column  with textbox

one column (TotalAmount) who will show the sum of two columns (Amount and Quantity)

When i enter amount and quantity i will automatically show the sum into totalamount column.

How can i do that controlling

and also plz tell me how can i set or get a Single column value of datagrid in C#

It is a windows application not the web

Plz help me

Great Thanks for this.