passing parameters from a web form to fme server workbench.

I've built six custom web form to pass variable to publicly available workbenchs. But I can't quite figure what the url should be in the webform so that the user input gets passed to the workbench. 

 

 

Webform: http://fmeserver.ncd.noaa.gov/encdirect_extract_overview.html 

 

 

Workbench: 

 

 

https://fmeserver.ncd.noaa.gov/fmeserver/repositories/encdirect_extract/orapub2multiformat_overview.fmw