What makes you jealous? How can you best handle those feelings?

This is a very good question for me, and probably a lot of ohter people out there.  An example of something that makes me jealous is when I know someone is able to do something that I also can do, let's take singing for example, and I would be trying out along side this other person for a solo, adn I know that I did very well with it, but then, the other person got chosen to sing the solo.  When finding out this result, I would initially feel like "how dare you?" and then feel a little steamed about it for a while.  But really, the best way to handle this sort of feeling is to just do the best you can for that particular situation and hope for the best, but also, keep an open mind about the chance that the total opposite could happen, and usually I pray to God to keep reminding me about both posibilities that are at stake.