ComboBox leave event .net 1.1

Hi All I'm trying to develop a windows based application and i'm stuck at the minute I have a update item form where it displays the item details. in the onload event i have the following private void UpdateItem_Load(object sender, System.EventArgs e) { //to get all suppliers update_changeSuppCB.Enabled = false; string getItemSupp = "SELECT suppliers_name FROM Suppliers"; //SqlCommand getItemSuppCmd = new SqlCommand(getItemSupp, conn); SqlDataAdapter getItemSuppAdp = new SqlDataAdapter(getItemSupp, conn); DataSet getItemSuppDs = new DataSet(); try { conn.Open(); //getItemSuppCmd.ExecuteReader(); //update_changeSuppCB. getItemSuppAdp.Fill(getItemSuppDs, "Suppliers"); update_changeSuppCB.DataSource = getItemSuppDs.Tables[0]; update_changeSuppCB.DisplayMember = "suppliers_name"; } catch (Exception ex) { MessageBox.Show(ex.ToString()); } finally { conn.Close(); } }//end of load event in the form i have a combo box with a leave event with the following code private void update_changeSuppCB_Leave(object sender, System.EventArgs e) { string suppName = update_changeSuppCB.Text; //now to get the id of the suppliers name (note i'm calling another class to get the suppliers id) int suppId = getCatSuppId.getSupplierId(suppName); //if the user selected a different supplier then go ahead with the change else do nothing if (suppName != update_suppliersTxt.Text) { string updateSupp = "UPDATE Items SET supplier_id = " + suppId + " WHERE id = " + update_itemIdTxt.Text; SqlCommand updateSuppCmd = new SqlCommand(updateSupp, conn); try { conn.Open(); updateSuppCmd.ExecuteNonQuery(); } catch(Exception ex) { MessageBox.Show(ex.ToString()); } finally { conn.Close(); } } } the problem is i'm getting "Invalid Operation Exception- The connection is already open" now this is happening because after executing this line update_changeSuppCB.DataSource = getItemSuppDs.Tables[0]; The leave event (private void UpdateItem_Load(object sender, System.EventArgs e)) is being called. Why is it being called.. shouldnt only be called after leaving away from the combobox. Thank you in advance