how to update the command using oledb in csharp in windows

Question

  how to update the command using oledb in csharp in windows application.

 Faculty code       textbox

 Faculty Name     textbox

Allocated hours   textbox

       

       Save code as follows;

        private Globalfunction GFun = new Globalfunction();

        private string sql;

       

 sql = "insert into Tb_Faculty_Details ([Faculty_Code], [Faculty_Name],[Allocated_Hours]) " + " values('" + txt_Faccode.Text + "','" + Txt_Facname.Text + "', " + txt_Hrs.Text + ")";

            try

            {

                GFun.error = "";

                GFun.InsertAccessData(sql);

                if (GFun.error.ToString() != "")

                {

                    MessageBox.Show(GFun.error.ToString(), "Error");

                    return;

                }

                GFun.OleDbcon.Close();

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

                return;

            }

Update code as follows;

 sql = "Update Tb_Faculty_Details set (Allocate_hours = '" + txt_Hrs.Text + "')  where Faculty_Code = ' " + txt_Faccode.Text + "'";

            try

            {

                GFun.error = "";

                GFun.InsertAccessData(sql);

                if (GFun.error.ToString() != "")

                {

                    MessageBox.Show(GFun.error.ToString(), "Error");

                    return;

                }

                GFun.OleDbcon.Close();

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

                return;

            }

i want to update only allocated hours after searching the record, i want to update the allocated hours.