Calculation in DataGridView cells
                            
                         
                        
                     
                 
                
                    
Hello sir,
i m making project for billing i want to make calculation in DataGridView cells when i click the cell it should be allow to input only numaric value and should be calculate with other cell and amount will be display in Net Amount cell. i dont know how can i do it . if you have any idea or any code then please give 
its Urgent 
Thanks in Advance 
Naim Khan