OK, if only the two global variables need to match it would be
if s1!=t1 then exit rules, skip outgoing action.
If both s1 and t1 have to equal 1 then
if s1!=1 then exit rules, skip outgoing action
if t1!=1 then exit rules, skip outgoing action
There are other ways to write it as well. This post has a lot of examples of more complex Boolean logic.
Steve Caldwell
Bome Customer Care
Also available for paid consulting services: bome@sniz.biz