its urgent

[gurm]

i hav my interview for visitor visa soon in nex 3 or 4 days.......my situation is this tht i am a student in ukraine studying medicine.i m in my 2 nd last semester of my studies..6 mths bfore my degree completes,my parents my brother all are green card holders,settled one year ago ,now i wish to visit them in new year as it has been 2 years since i met them...i m really confused abt the situation ..my mother has already filed an immigration petion last january since i culdnt move with them as i was above 21 yrs of age when they immigrated....now i want to visit them i have a formal invitation from my father and all documents required...can any one suggest wht explanation shuld i produce b fore the counslar ...so tht he or she is convinced tht i m a genuine candidate for the visa..and tht i sincerely wish to study and return after my visit to usa....since i m a potential immigrant...any help wuld b welcome ..plz help .....reply as soon as u read...thx in advance