Datagrid validation..

[buterfly0707]

hi..

i want to check weather datagrid particular cell is empty. whet i wan to do is :
if in a datagrid row if 1st 2 cells are not null and if i did not enter a value to 3rd cell then i go to enter new values to next row then i want o give error fill the 3rd cell.

so far what i did was:
here dgvItem is my datagrid. i have written this code in cell_enter event

            try
            {
                if (dgvItem.CurrentCell.ColumnIndex == 1)
                {
                //for (int i = 0; i < dgvItem.Rows.Count+1; i++)
               // if (dgvItem.CurrentRow.Index==0)
                //{
                    
                    string itemDis;
                    itemDis = Convert.ToString(dgvItem.CurrentRow.Cells[1].Value);
                    //itemDis = Convert.ToString(dgvItem.Rows[i].Cells[1].Value);
                    string itemQty;
                    itemQty = Convert.ToString(dgvItem.CurrentRow.Cells[3].Value);
                    //itemQty = Convert.ToString(dgvItem.Rows[i].Cells[3].Value);
                    if (itemDis != "" && itemQty == "")
                    {
                        DialogResult reply = MessageBox.Show("Please Fill the data", "", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        if (reply == DialogResult.OK)
                        {
                            dgvItem.Focus();
                        }
                    }
                }
            }
            catch { }

i have tried many ways to do this as i have comment in the code above. but the message is coming when ever i click on the cell.
meaning my 1st cell is a combobox.so when i click on the 2nd cell relevent value for combobox selected value have to fill to 2nd cell. so even when i clik on 2nd cell before even go to next row the message is comming.

so what can i do ?? how can i do this. i hope what im asking is clear over here?

thank you