[ic] Authorize.net Change to auth_only

[interchange-users@icdevgroup.org (Michael Stearne)]

By default authorize.net is set up to capture transactions 
automatically.  We would like to change the set up to only authorize the 
card and not actually charge it until we ship the product.  The 
aurthorize.net people told me to set the variable x_Type=auth_only which 
will do what I described above.  My question is what file or 
configuration do I change in IC to control this parmeter.  

/usr/lib/interchange/lib/Vend/Payment/AuthorizeNet.pm mentions:

The type of transaction to be run. Valid values are:

    Interchange         AuthorizeNet
    ----------------    -----------------
        auth            AUTH_ONLY
        return          CREDIT
        reverse         PRIOR_AUTH_CAPTURE
        sale            AUTH_CAPTURE
        settle          CAPTURE_ONLY
        void            VOID

but I do not know the IC variable to change to activate "auth".

Thanks,
Michael Stearne