Oracle Form - show blank screen after creating domain

Hi experts,

I'm a newbie on Oracle form. I installed form12  on Win7 and created base domain and then started Node Manager &startWebLogic

However:
1.) WLS_FORMS cannot auto start
2.) Even started WLS_FORMS manually from EM, it only show blank screen from the test.fmx (like below)
http://localhost:9001/forms/frmservlet?form=C:\Oracle\Middleware\Oracle_Home\forms\test.fmx

Please advice what's wrong with it and how to fix this problem?

Thanks a lot in advance!