Hello Everyone!!

I would like to know if someone has changed the visa status from F1 to M1 because I need to change the Visa Status to M1 and fro this I need your suggestion. Could anyone tell me how long will it take to change the Status of Visa??? and also Is it possible if USA or I have to go to another my country for the change of Status?? I would really be happy if anyone suggest me in this matter.