The universal chargers do not have a good reliability history. Also the universals may not match the power requirements exactly for your laptop. If you can try to find an original working OEM on Ebay.
Agreed.. aftermarket/universal adapters do not go through the same stress testing as OEM equipment will. If you can get the original via ebay, its much much cheaper and more reliable than any cheapy universal.
Stay away from ordering direct from manufacturer though; they keep the cost of these items extremely high so they keep some stock available for warranty work. This way people don't buy out their replacement/fix stock.
Have to pay attention to voltage requirements. I have seen them range from 8 volts to 19 volts. The amperage is not as important, but the higher the amps of the charger, the more efficient it is in regards to operating the lap-top and charging the battery.