DataGrid View

[danasegarane]

Dear All,
I am placing a combo box in datagrid view cell.I am using this code.The problem is that when i press the tab key the entered values get into the
combo box dropdown list.But when I press the Enter key unfortunately not

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
              DataGridViewColumns.Add("Name", "Name")
              DataGridViewColumns.Add("Age", "Age")
              DataGridViewColumns.Add("Phone", "Phone")
              Dim comboboxcol As New DataGridViewComboBoxColumn
              comboboxcol.HeaderText = "Type"
                 comboboxcol.Items.Add("Type A")
   
              comboboxcol.Items.Add("Type B")
   
              comboboxcol.Items.Add("Type C")
  
              comboboxcol.Items.Add("Type D")
  
              DataGridViewColumns.Add(comboboxcol)
  
       
  
          End Sub
  
       
  
          Private Sub DataGridView1_EditingControlShowing(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DataGridViewEditingControlShowing
  
              Dim combocol As DataGridViewComboBoxColumn = DataGridViewColumns(3)
  
              If (DataGridViewCurrentCellAddress.X = combocol.DisplayIndex) Then
  
                  Dim cbbox As ComboBox = e.Control
  
                  If cbbox IsNot Nothing Then
  
                      cbbox.DropDownStyle = ComboBoxStyle.DropDown
  
                  End If
  
       
  
              End If
  
          End Sub
  
       
  
          Private Sub DataGridView1_CellValidating(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellValidatingEventArgs) Handles DataGridViewCellValidating
  
              Dim cbcol As DataGridViewComboBoxColumn = DataGridViewColumns(3)
  
              If (e.ColumnIndex = cbcol.DisplayIndex) Then
  
                  If Not cbcol.Items.Contains(e.FormattedValue) Then
  
                      cbcol.Items.Add(e.FormattedValue)  'Errror Line
  
                  End If
  
              End If
  
          End Sub

How can I solve this problem
Thanks in advance
Dana