> I have a combo box that show 2 fields in form. The 2nd field is set 50 characters long in table.
> Is it possible to set combo box to show the 2nd fields with dynamic width, instead of showing long empty space since the data stored in table may be just 20 characters?

I don't know for sure what do you call "dynamic width". You can set the Columnwidths property of the combo box to anything you want (not necesarilly the actual size of the field), in pixels.

For example: 100,200,0

In this case the last column exists but is NOT displayed. This is useful to hide primary keys and other related values.

Hope this helps.