MS Word filename from bookmarks with VBA - vba

Question

Assuming I have:
a word template including macro: custom_template.dotm;
two bookmarks in this template: 'first_name" and "last_name".
I would like that on "Save" event, in the dialog box, the application proposes to user, instead of "document1", and only if relative bookmarks exist, the filename "Document of first_name second_name.docx".
Can anybody explain me how to achieve this with VBA?
Thanks.
=== UPDATE ===
Now I've this code, working well when I execute it.
I would like it runs automatically when user clicks on "save document".
Sub Demo()
Dim sFlNm As String
With ActiveDocument
sFlNm = "Document of " & .Bookmarks("first_name").Range.Text & " " & .Bookmarks("last_name").Range.Text
End With
With Dialogs(wdDialogFileSaveAs)
.Name = sFlNm
.Show
End With
End Sub

Answer 1

For a macro to run at the client's end, you would have to send a macro-enabled template or document. Many people who are running anti-virus software will get a warning of a possible Word virus. Then the user will have to manually enable the macros. Are they going to bother?
Making it run automatically with a Save command may have unintended consequences. You'll have to check whether the bookmarks have actually been filled, and using the Save command while you're revising the document can save it with a new file name. But you asked, so here's how: rename the macro as FileSave. Then when you choose Ctrl + S or File>Save in Word, the dialog will automatically pop up:
Sub FileSave()
Dim sFlNm As String
With ActiveDocument
sFlNm = "Document of " & .Bookmarks("first_name").Range.Text & " " & .Bookmarks("last_name").Range.Text
End With
With Dialogs(wdDialogFileSaveAs)
.Name = sFlNm
.Show
End With
End Sub
In Word, to create a macro that runs automatically when you choose a Word command, follow these steps:
Choose Developer>Macros.
Change the Macros in dropdown to Word commands.
Choose the command name you want to re-purpose.
Change the Macros in dropdown back to the macro-enabled document or template that you're developing.
Click on the Create button. A new macro is created in the VBE with the correct command name. Fill in the macro with whatever you want the macro to do.