How Do You Make If.then.else Do Two Stuff On One Line?

is it possible to do a insert, add, and a redirect all on the same page?

for example... signup.asp. there's a text box labeled Acctid. If you don't have an acctid please enter "0000" otherwise enter one. This box is used to see if they have an existing account in the database by using an UPDATE query and if they don't it does an INSERT query with acctid = 0000 for all non customers. What I want the if.then.else statement to do is to

If acctid = "0000" then
conn.execute acct_add
(and if sucessful to response.redirect "/yay.asp"
Else if NOT acctid = "0000" then
conn.execute acct_update

(but I want it to return an error if the update wasn't sucessful either because the acount doesn't exist or watever and if the update was sucessful to response.redirect "/yay.asp") END IF

Do ya get it?