datagridview error plz help me

[selvakumari]

int n = 0;
ushort[] data = new ushort[8];
ushort[] dataCompare = new ushort[8];
ushort[] sendData = new ushort[8];
ushort id,scalefactor,currentValue;
int numValue = Convert.ToInt32(currentCell.RowIndex.ToString());
string[] cellType = currentCell.ToString().Split(new char[] { ' ' });
switch (cellType[0])
{
case "DataGridViewTextBoxCell":
if (numValue < _responseparser.tableId.Count)
{
id = ushort.Parse(_responseparser.tableId[numValue].ToString());

string editValue = currentCell.EditedFormattedValue.ToString();
//Getting error in this line "Input string was not in correct format"
int s = Convert.ToInt32(editValue); scalefactor = ushort.Parse(_responseparser.tableScaleFactor[numValue].ToString());
decimal saveValue = ((decimal)s / (decimal)scalefactor);
data[0] =saveValue;

CommMngr.SelectedUnit.Modbus.SetParameter(id, data);
dataCompare = CommMngr.SelectedUnit.Modbus.GetParameter(id);
if (data[0] != dataCompare[0])
{
MessageBox.Show("Value Edit Failed, ModBus Return Value = " + dataCompare[0]);
}
}
break;


bolded line gives me a exception "Input string was not in correct format"