Hi,
Have a look at the
FileSystemObject[
^] found in the scripting runtime object (SCRRUN.DLL).
This will provide you the means to check if the image file exists, and then set your default image if it does not.
After you've setup your project reference to the scripting runtime(see the link above), something like this should be what you're looking for:
Dim oFso As New Scripting.FileSystemObject
If(oFso.FileExists(App.Path & "\" & Combo1.Text & ".jpg") Then
Picture2.Picture = LoadPicture(App.Path & "\" & Combo1.Text & ".jpg")
Else
Picture2.Picture = LoadPicture(App.Path & "\defaultImage.jpg")
End If
... hope it helps.