Millisecond Forums

Dear all,
At the beginning of our experiment, I would like to request the postal code of our participants and only allow people who live in certain areas to participate in our experiment. For this purpose, I have created the following:
<textbox PLZ>
/ caption = "xxx postal code xxx."
/ required = true
/ mask = decimal
</textbox>

<values>
/PLZ_correct = 0
</values>

<surveypage s_einwilligung>
/ questions = [1 = Einwilligung; 2 = Alter; 3 = PLZ]
/ ontrialend = [if (textbox.PLZ.response == "20259" || "20251" || "20249") values.PLZ_correct +=1
else values.PLZ_correct +=0]
</surveypage>

<surveypage s_einwilligung2>
/ questions = [1 = Sehen; 2 = Erkrankung; 3= LRS]
/ branch = [if (values.PLZ_correct == 1) survey.X
     else surveypage.s_ende;]
</surveypage>
Unfortunately, it does not work, and I can not find the error. For any help, I would be very grateful!
All the best,
Djo