[Asterisk-Users] Checking Return Codes

[Glenn A. Thompson]

Hi,

I must be blind, how does one check then act upon the return code from 
the previous command?
For instance, "Answer" says it can return non zero.  How do I check for 
that.  It doesn't set any other variables like Dial does.

In this case, all I'm really trying to do is not answer if the line has 
already been picked up.  Do I have to make sure the channel is available 
before I issue the Answer cmd.

Thanks,
Glenn