Tracking losses in the world markets the Sensex is likely to open on a weak note. On the positive FIIs have been net buyers in the cash market for the last one week. However, US Federal Reserve meet early next week for a possible interest rate hike may weigh on the market sentiment in the short-term.On the upside, the index is likely to face resistance around 10,800-10,815-10,830 levels. On the downside, the index has support around 10,700-10,685-10,670 levels.