Check Box Field Doesn't Work in Online Custom Record Form

I created an online custom record form and attached it to a custom record type. In the form, I added some check box field and added field tags to a form HTML template:
<p>Endorsement(s):<br />
Hazardous Material<NLCUSTRECORD_JOBAPP_ENDORSEMENTS_HM>
Passengers<NLCUSTRECORD_JOBAPP_ENDORSEMENTS_PASSENGER>
Tankers<NLCUSTRECORD_JOBAPP_ENDORSEMENTS_TANKERS>
Tank with Hazardous Materials<NLCUSTRECORD_JOBAPP_ENDORSEMENTS_TANKHM>
School Bus<NLCUSTRECORD_JOBAPP_ENDORSEMENTS_SCHOOLBUS>
Double/Triple trailers<NLCUSTRECORD_JOBAPP_ENDORSEMENTS_TRAILERS>
</p>

But the problem is when I submit the form, the check box won't be checked in the received record in Netsuite. The selected item goes into Netsuite, but the check box still shows unchecked. I am wondering if there are any missing settings in these check box fields.