Can I change back to F1 ? reddog2005-11-17 20:05:02

I got my PERM granted. My employer will apply I-140 for me.
At the same time, I am a part-time PhD student.
Can I switch back to F1 if I want to be a full time student? In which stage, I can not?

Thanks for your suggestions and help.

Best regards

Give up PERM?!