Inserting/replacing picture with vba

[Sean]

I would like to be able to click on an image control to
bring up the InsertPicture dialog and replace the image
frame with a user defined image (via browsing). However,
my image control is in the header of the document. I have
been using the a macro upon clicking to try and do this
but it doesn't seem to work. The dialog shows up, but
when I choose an image and insert it doesn't get placed in
the frame/control. Is there a better way?

Private Sub Image_Click()
Dialog(wdDialogInsertPicture).Show
End Sub

Also i had one other question about combo boxes. Is there
a way to make the next item below a default display when a
button is clicked?
cboDayofWeek.Value = ????NextItem????

Thanks. All advice has been a huge help.