C# refresh access database

I am able to Save Data to a Access databse , now when i add new entry i try to refresh the database but the new entry dont show until i close the program and open it back up. I have 2 buttons one Update and the other Refresh. I am using Parameters. It would be better to use one meathod to do both (thats over my head at the moment) so i have 2 buttons. I dont get any errors when i try to Refresh so I dont know where to start.
 
Thanks 
 
My Update code working fine.

<pre lang="c#"><pre>private void btnUpdate_Clicked(object sender, RoutedEventArgs e)  
       {  
           using (var myCon = new OleDbConnection(ConfigurationManager.ConnectionStrings["Connection"].ToString()))  
           {  
               using (var myCmd = new OleDbCommand("insert into [Sheet1](Box1,Box2,Box3,Box4,Box5,Box6,Box7,Box8)Values(@nm1,@nm2,@nm3,@nm4,@nm5,@nm6,@nm7,@nm8)", myCon))  
               {                      
                   myCmd.Parameters.AddWithValue("@nm1", txt_Box1.Text);  
                   myCmd.Parameters.AddWithValue("@nm2", txt_Box2.Text);  
                   myCmd.Parameters.AddWithValue("@nm3", txt_Box3.Text);  
                   myCmd.Parameters.AddWithValue("@nm4", txt_Box4.Text);  
                   myCmd.Parameters.AddWithValue("@nm5", TXT_Box5.Text);  
                   myCmd.Parameters.AddWithValue("@nm6", txt_Box6.Text);  
                   myCmd.Parameters.AddWithValue("@nm7", txt_Box7.Text);  
                   myCmd.Parameters.AddWithValue("@nm8", txt_Box8.Text);  
  
                   try  
                   {  
                       myCon.Open();  
                       int z = myCmd.ExecuteNonQuery();  
                       if (z > 0)  
                       {  
                           MessageBox.Show("Data Inserted");  
  
                      }  
  
                   }  
                   catch (Exception ex)  
                   {  
                        MessageBox.Show(ex.Message);
                        return;
                   }  
               }  
           }  
  
              
       }  

private void btn_Refresh_Click(object sender, EventArgs e)  
        {  
  
            using (var myCon = new OleDbConnection(ConfigurationManager.ConnectionStrings["Connection"].ToString()))  
            {  
                using (var myCmd = new OleDbCommand("UPDATE Sheet1 SET Box1 =@nm1,Box2 = @nm2, Box3=@nm3, Box4 = @nm4, Box5 = @nm5,Box6  = @nm6, Box7 = @nm7 WHERE Box8 = @nm8", myCon))  
                {                      
                    myCmd.Parameters.AddWithValue("@nm1", txt_Box1.Text);  
                    myCmd.Parameters.AddWithValue("@nm2", txt_Box2.Text);  
                    myCmd.Parameters.AddWithValue("@nm3", txt_Box3.Text);  
                    myCmd.Parameters.AddWithValue("@nm4", txt_Box4.Text);  
                    myCmd.Parameters.AddWithValue("@nm5", TXT_Box5.Text);  
                    myCmd.Parameters.AddWithValue("@nm6", txt_Box6.Text);  
                    myCmd.Parameters.AddWithValue("@nm7", txt_Box7.Text);  
                    myCmd.Parameters.AddWithValue("@nm8", txt_Box8.Text);  
  
                    try  
                    {  
                        myCon.Open();  
                        int z = myCmd.ExecuteNonQuery();  
                        MessageBox.Show("Data Updated");  
                         
                    }  
                    catch (Exception ex)  
                    {  
                        //Handle exception as needed  
                    }  
                }  
            }  
  
             
        }  

private void loadgrid()
      {
          OleDbConnection con = new OleDbConnection();
          con.ConnectionString = ConfigurationManager.ConnectionStrings["Connection"].ToString();
          con.Open();
          OleDbCommand cmd = new OleDbCommand();
          cmd.CommandText = "Select * from [Sheet1]";
          cmd.Connection = con;
          OleDbDataReader rd = cmd.ExecuteReader();
          dataGrid.ItemsSource = rd;

      }