I have been playing with the TopMostItem, but the combo does not show the TopMostDescription when navigating through the records (ex, Next, prior, etc.) unless I put code to Requery the combo in the BO.Navigated event which makes no sense if you have to do it in all your forms for all your comboboxes.

Also, when selecting the TopMostItem as a valid option in the combo and trying to save will generate an error due to the value of the TopMostValue either -1 or 0.

In my Case I am binding the combo to an Integer field and have the following values in the TopMostItem: [Select a Company],0 or  [Select a Company],-1

What am I doing wrong here?

I put together another video so you can see the problem in action:

http://www.progytech.com/videos/TopMostItem\TopMostItem.html

Trent, the problem is when going to the next parent record and there is no record in the child BO, the combo will always show the last selected value and it is shown in the video.

In my case all the tables I use that will be shown in a combo are Integer type, and -1 or 0 are not valid values, so here is where I get confused on what value to use in the TopMostValue property.

In VFP this problem does not exist, if there is not value selected in the combo it will be shown as blank.  Now I thought the TopMostItem feature would just show the TopMostDescription in the combo when not value has been selected by the user, so I am definitely missing something here.

I have this very same scenerio setup hundreds of times.  You are missing one of the following items:

1. The record bound to the combo does not have a value of -1.  All the topmost item does is create another record to which can be bound at the top of the combo.  So more than likely your default value should be 0, not -1.  But regardless, it has to be a value to which can be bound.  If 0 or -1 are not valid values, great.  When a new record is created, set the default value to a -1 (it should already be a 0 by default), and then it would line up and still require a selection.
2. You do not have the BindingProperty correctly assigned. (i.e. binding to Text and expected the SelectedValue to line up).
3. Don't have the control bound at all.
4. Have provided an illegal value in the TopMostValue

That is basics wraps it up.  I know that you have to have one of these scenarios going on.

Just out of curiosity, did you take a look at my video? http://www.progytech.com/videos/TopMostItem/TopMostItem.html

Besides the problem with the TopMostItem, there is also the problem when navigating the parent record and having a combo on a child in the same form and this does not update correctly or blank out its display value if there is not child record in the BO.

Any comments on this one?