more then one method at time

Dear friends,
                    I am using asp.net2005. I have three method, suppose a(),b(),c().
 
  I want to run the methods on button click.
 a(),b() and c() should run at time .If a() method fail to run then b() and c() should not me run. if b() fail to run then a() and c() should not be run ?
 
any method is available?
 
Please help ASAP.
 
Thanks in advance..
 
With regards
Viveck kummar
 
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