C# datagridview check if checkbox is checked in column : I have datagridview column with checkboxes. I want to check if there is a selected Row in this column. If its not i want to display msgbox. I can check columns by this but im receving multiple msgboxes for every unchecked row. How to change it to receive only one msgbox? 

Thanks

    foreach (DataGridViewRow row in dataGridView1.Rows)
            {
                DataGridViewCheckBoxCell cell = row.Cells[5] as DataGridViewCheckBoxCell;

                //We don't want a null exception!
                if (cell.Value == null)
                {
                    MessageBox.Show("Nie zaznaczono pola!");
                }
                

            }