2 errors 1) args should be an array form.add_button("Print_Tag", URL("tagprint", args=[record.bike_identifier])) instead of form.add_button("Print_Tag", URL("tagprint", args=record.bike_identifier))
2) if you pass it to args then retrieve it from args, not from vars req = request.args(0) instead of req = request.vars['bike_identifier'] do you understand differences between request.args and request.vars ? * * * * * * * * --