Option Call Writing

I write options on commodities/stocks, no haram companies.  If I own the underlying stock what is wrong with me writing calls against them to earn some extra profit? If the option buyer wants to excercise his right to buy the stock that is up to them and I am obligated to sell it.

How is this a form of gambling? I do not understand. Because of risk? Everything is a risk; opening a business, buying a home, riding your bike! Investing isn't just flipping a coin, a lot of this strives on many factors, enconomy, weather, volatility, etc... Technical analysis is a tool that measures future probabilities and I can see where that might be haram.

 I have read scholars opinions, but most do not understand the strategy of options.  Can someone help me with this, this is my second income, and my first sucks!!! If this is haram I have to change my whole lifestyle! I hate to be a downer, but everything I look into has the big Haram question, so what is halal?

-Frustrated and possibly soon to be broke.