where to put the stock gain?

I am wondering where and how to report the income in China in Form 1040 ? line 7 or line 21 ( other income)
The trouble is that there is no W2 form in China ,so how to report the income in China? Can anybody help? Stp ,Fajushi or H-1B_tax? Please help.
Another question is how to report the net gain from the stock.I gained few hundreds dollars from the stock market last year ,should I just put the net gain in line 13a ands also file a schedule D together? or just ignore the schedule D since this is the only money I got besides my salary.Does anybody have any ideas??
Thanks a lot!