Search in LINQ to SQL

Function GetTypeFromTableName(ByVal _TableName As String, ByVal _DataContext As DataContext)

    Dim Mytype As Type = (From t In _DataContext.Mapping.GetTables Where t.TableName = "dbo." + _TableName Select t.RowType.Type).SingleOrDefault
    Return Mytype

End Function

Dim DBA As New LINQDataContext
_TBLName="City"
TableType = GetTypeFromTableName(_TBLName, DBA)

Dim GridQuery = From T In DBA.GetTable(TableType) Select T

If Chk.Checked Then
    CallByName(obj, "CName", CallType.Set, Txt_Name.Text)
    GridQuery = From T In DBA.GetTable(TableType) Where T Like obj
End If