Dynamic grid problem

int rowIndex = 0;

if (ViewState["CurrentTable1"] != null)
{

   DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable1"];
   DataTable DtLast = null;
   DataRow drCurrentRow = null;

   if (dtCurrentTable.Rows.Count > 0)
   {
       for (int i = 1; i <= dtCurrentTable.Rows.Count; i++)
       {
           //extract the TextBox values

           TextBox box1 = (TextBox)Gridview1.Rows[rowIndex].
                Cells[1].FindControl("TxtName");
           TextBox box2 = (TextBox)Gridview1.Rows[rowIndex].
                Cells[2].FindControl("TxtStatus");
           TextBox box3 = (TextBox)Gridview1.Rows[rowIndex].
                Cells[3].FindControl("TxtAddress");
           drCurrentRow = dtCurrentTable.NewRow();
           drCurrentRow["SrNo"] = i + 1;
           drCurrentRow["Name"] = box1.Text;
           drCurrentRow["Status"] = box2.Text;
           drCurrentRow["Address"] = box3.Text;
           rowIndex++;
           DtLast.Rows.Add(drCurrentRow);
       }

       //add new row to DataTable
                  

       //Store the current data to ViewState
       ViewState["CurrentTable1"] = dtCurrentTable;

       //Rebind the Grid with the current data
       Gridview1.DataSource = dtCurrentTable;
       Gridview1.DataBind();
    }
}