Stopping order process with displaying clear error why it stopped. Possible?

[jareq]

Hello, is there possible to stop order process in event hooks and display nice message (i thought about javascript popup alert box) to customer why the process was stopped. At this point i know how to stop it by just typing exit(); but im wondering if there is any api that could display clear error for customer, or maybe do you have any idea?

 

second question:

how to pass $globalmessage to ShoppingCartValidateCheckout hook ?

How this works? I have already tried just $errormessage = "error bla bla";

or return $errormessage;

Or did i missunderstood it and it works another way and passing error by itself when occurs? And i can display it by print($errormessage) ?

Edited February 12, 2012 by jareq

[jareq]

how to pass $globalmessage to ShoppingCartValidateCheckout hook ?

Sorry, i mean $errormessage.

(cant edit now)