help me .... how to clear data in specific column in

MSDN has a few examples in it and for once a clear explanation ie

' Declare a new DataGridTableStyle in the
' declarations area of your form.
Dim ts As DataGridTableStyle = New DataGridTableStyle()

Sub DeleteColumn()
   ' Set the DataGridTableStyle.MappingName property
   ' to the table in the data source to map to.
   ts.MappingName = DataGrid1.DataMember

   ' Add it to the datagrid's TableStyles collection

   ' Delete the first column (index 0)
End Sub

either that or just clear the data fields in the column or delete the coumn and add it back afterwards.