update database from datatable using commandbuilder

[gomathinayagam]

hai,

am only beginer in c#...
i am trying to connect database with webform. using a technique that the fields of the table and the controls in a form are named same...then i try get the controls and check their name with
database fields names if they equal then i plan to do addition or update etc...

MY PROBLEM is, i am succeed in addition, but know i try to edit the same field. i assign the datatable and made the changes in that datatable..now the datatable is edited..i check that...now i try to update it into database using commandbuilder. ..nothing will updated ...my codes are below
PLZ HELP ME......

for add a new row in a table i use below comand it will work....

create a datatable and assign the required table using select command
 DataRow dr = dt.NewRow();
         foreach (Control c in this.form1.Controls)
         {
             for (int i = 0; i <= dt.Columns.Count-1; i++)
             {
                 if (dt.Columns[i].ColumnName == c.ID)
                 {
                     switch (c.GetType().ToString())
                     {
                         case "System.Web.UI.WebControls.TextBox":
                             TextBox tx = (TextBox)c;
                                dr[c.ID]  =tx.Text; 
                               break;
                           case "System.Web.UI.WebControls.DropDownList":
                               DropDownList  drop = (DropDownList)c;
                               dr[c.ID] = drop.Text;
                               break;
                     }
                 }
             }
       }
       dt.Rows.Add(dr);
       string constr1;
       SqlConnection sqlcon1;
       constr1 = "server=dotnet6;database=staff;user id=sa;password=sa;";
       sqlcon1 = new SqlConnection(constr1);
       string sqlquery = "select * from staffdetails";
       SqlDataAdapter da = new SqlDataAdapter(sqlquery,sqlcon1);
       SqlCommandBuilder blr = new SqlCommandBuilder(da);
       da.Update(dt);
       da.Dispose();
 
BUT FOR EDIT A ALREADY ONE I WROTE THE FOLLOW..IT WON'T WORK..
 
DataRow dr = dt.Rows[dt.Rows.Count - 1];
       dr.BeginEdit();
       foreach (Control c in this.form1.Controls)
       {
           for (int i = 0; i <= dt.Columns.Count - 1; i++)
           {
               if (dt.Columns[i].ColumnName == c.ID)
               {
                   switch (c.GetType().ToString())
                   {
                       case "System.Web.UI.WebControls.TextBox":
                           TextBox tx = (TextBox)c;
                           dr[c.ID] =tx.Text;
                           break;
                       case "System.Web.UI.WebControls.DropDownList":
                           DropDownList drop = (DropDownList)c;
                           dr[c.ID] = drop.Text;
                           break;
                   }
 
               }
           }
       }
       dt.AcceptChanges();
       dr.EndEdit();
       string constr1;
       SqlConnection sqlcon1;
       constr1 = "server=dotnet6;database=staff;user id=sa;password=sa;";
       sqlcon1 = new SqlConnection(constr1);
       string sqlquery = "select * from staffdetails";
       SqlDataAdapter da = new SqlDataAdapter(sqlquery, sqlcon1);
       SqlCommandBuilder blr = new SqlCommandBuilder(da);
       da.Update(dt);
      da.Dispose();

why... plz help me.. i'm only a beginer so if i made some major mistakes don't blame me...
plzz help me

[CyberSoftHari]

dt.AcceptChanges();
dr.EndEdit();

Chech here, dt.AcceptChanges() ; and dr.EndEdit();
I suggest to use sql update query.
(BTW, why don’t you use code tags for your code? and i am unable to point the line number.)