prevent datagridview cells from creating new row.

Set DataGridView1-AllowUserToAddRows as False 
Private Sub DataGridView1_CellContentClick1(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick

            If DataGridView1.Rows.Count > 0 Then
                If e.RowIndex >= 0 Then
                    temprowid = e.RowIndex
                 End If
           End If
End Sub
Private Sub DataGridView1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles DataGridView1.KeyPress
          //if (e.KeyChar == (char)Keys.Tab) //--From CSharp
           If e.KeyChar.Equals(Keys.Tab) Then //--Check This is Correct or Not
            If temprowid >= 0 Then
               If (DataGridView1.Columns(DataGridView1.CurrentCell.ColumnIndex()).HeaderText.Equals("LastCellName")) Then
                   BindingSource1.AddNew()
               End If
            End If
          End If
   End Sub

int temprowid=0;
private void DataGridView1_CellContentClick1(object sender, DataGridViewCellCancelEventArgs e)
{
     if(DataGridView1.Rows.Count > 0 )
     {
        if( e.RowIndex >= 0)
        temprowid = e.RowIndex;
     }
}
private void DataGridView1_KeyPress(object sender, KeyPressEventArgs e)
{
   if (e.KeyChar == (char)Keys.Tab)
   {
      if(temprowid >= 0) 
      {
if(DataGridView1.Columns[DataGridView1.CurrentCell.ColumnIndex].HeaderText.Equals("LastCellName"))
         FillGrid(1);
      }
   }
}
Private Void FillGrid(int RowCount)
{
     foreach (DataGridViewRow r in DataGridView1.Rows)
     {
        DataGridView1.Rows.Remove(r);
     }
     DataGridView1.DataSource = null;
     if (DataGridView1.Columns.Count > 0)
     {
          DataGridView1.Columns.Clear();
     }
     DataTable dt=new DataTable()
     dt=dc.GetDataTable("Select Statement"); //--Returns DataTable
     if(Rowount > 0)
     {
        For(int i=0;i<RowCount;i++)
        {
           DataRow dr = dt.NewRow();
           dt.Rows.Add(dr);
        }
     }
      DataGridView1.DataSource=dt;
}