The Pass Discount main action button in Sales > Tools > Actions can be set as a main button using:

 

 

Selecting the Pass Discount button brings up a list of all guests currently in the sale. The operator can select one of these guests or can choose search to bring up the Advanced Guest Lookup dialog and search for a guest not in the sale. If there are no guests in the sale, the lookup dialog appears immediately. After selecting a guest, a list of all valid passes for that guest is shown and one of these passes may be selected. Sales then applies the Sales screen action macros associated with that pass as though %E+pass_no had been swiped.

For a short video demonstrating this functionality, see http://portal.siriusware.com/docs/videos/using_the_pass_discounts_button_2009_nov_3.pdf. Requires Acrobat/Reader X and Flash. Reader and Flash are available for free from http://www.adobe.com.