{
if (dgInvoiceList.SelectedRows[0].Cells["TransactionComplete"].Value.Equals(false)) //Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

}

why is this?how to solve?
Can i disable the cells ,as when addinvoice button is clicked windows form appears ,for edit also windows form appears,upon saving the values sit in datagridview

So can I disable the cells so that if user clicks on cells this error wont appear

If i disable willl i be able to edit or add when I click buttons??

private void dgInvoiceList_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)

//check that the header is not clicked on

if (e.RowIndex >= 0)

dgInvoiceList.SelectionMode = DataGridViewSelectionMode.FullRowSelect;

try

if (dgInvoiceList.SelectedRows[0].Cells["TranscationComplete"].Value.Equals(false))

dgInvoiceList.SelectionMode = DataGridViewSelectionMode.FullRowSelect;

btnEditInvoice.Enabled = true;

btnDeleteInvoice.Enabled = true;

txtDiscount.Enabled = false;

txtTax.Enabled = false;

txtTotal.Enabled = false;

btnComputeTotal.Enabled = false;

groupBox2.Enabled = false;

btnAddNewDetail.Enabled = false;

btnDeleteInvoiceDetails.Enabled = false;

btnsave.Enabled = false;

dgInvoiceList.Rows[e.RowIndex].Selected = true;

else

txtTotal.Enabled = false;

btnsave.Enabled = false;

btnEditInvoice.Enabled = false;

btnDeleteInvoice.Enabled = false;

catch (Exception ex)

throw (ex);