button to update external file links?

I want to put a button on my sheet which will update all external links.

The links are files EX1 to EX10 and will not change. All i need is the code which updates these links via vba.

thanks

trying to work out the code to update all workbook links via vba

tried this from the help file

ActiveWorkbook.UpdateLink Name:=ActiveWorkbook.LinkSources

and i get an error saying "method 'updatelink' of object '_workbook' failed"

my code is

Application.DisplayAlerts = False
ActiveWorkbook.UpdateLink Name:=ActiveWorkbook.LinkSources
Application.DisplayAlerts = True

some of the links will not be valid as the files do not exist so i have turned alerts off to stop the errors. with alerts on, it asks for the location of all the missing files one at a time and then at the end it comes up with the same error as above.

any ideas how i can solve this? I do not want any prompting of any kind, just click the button and links that can be updated are updated, and the others are left.