Add Observation without Question Concept throws NullPointerException

When on the Manage Obs --> Add Obs page, if you don't choose a question concept, you get this ugly error. The solution is to catch this and show a nice pink box to the user.

2012-07-05 19:05:42.896::WARN: /openmrs/admin/observations/obs.form
java.lang.NullPointerException
at org.openmrs.web.controller.observation.ObsFormController.onBind(ObsFormController.java:110)
at org.springframework.web.servlet.mvc.BaseCommandController.onBind(BaseCommandController.java:518)
at org.springframework.web.servlet.mvc.BaseCommandController.bindAndValidate(BaseCommandController.java:395)
at org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:266)
at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
at
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