i am also entering new data with these combos(more than one).

What do you mean? You mean you are adding new items to the combo's List? If this is the case, all you need is code like this in the combo's valid(). Assuming that the RowSource type is 2-Alias or 6-Fields (for example):

IF NOT EMPTY( This.DisplayValue ) AND This.ListIndex = 0
  APPEND BLANK IN MyAlias
  REPLACE DescriptionField WITH This.DisplayValue IN MyAlias
  This.Requery()
ENDIF