This is not really an Immigration question. But my understanding is that of the amount is small, you should not have issues, if it is a big amount, you might. The rules are determined by those selling the tickets and organizing the competition...
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Please see the answer to your other question.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.