Disabling the auto response to reply from get-url

Probably an obvious question but how do I stop the automatic SMS back to 
the user of any response triggered by the get-utl I specify.

For example 

get-url = http://do something

and when I run do-something it replies 'done', however I don't want to 
send 'done' to the user.

? Thanks

Alex

-- 
Alex Judd
http://www.skywire.co.uk