If your laptop has 2 video outputs (hdmi, dvi, vga) regardless of the combination, you technically should be able to hook up more than one monitor. If you have your screen that is attached to the laptop AND only one of those outputs then you'd just be able to hook one other monitor up besides the screen attached to the laptop. If you're trying to attach more than that then you'd need to have a 2nd display port available which generally comes from a more powerful video card but I'm not sure how cheap or possible it is to put a video card in a laptop let alone a slim? (sounds smaller, probably less options if any).
My laptop has a function button that lets me switch between different options. FN + f7 I think it is. Anyway, there's 3 options for mine when I hit the button 3 times. One just has the laptop screen on, one turns the secondary monitor on, and one turns both of them on at the same time. After this, once you have both screens on, you have to go into your settings on the computer, where you set the resolution (right click desktop -> screen resolution) and setup the screens to be whatever resolution you want. Also on that same screen, if you click on the monitors shown (1 and 2) and drag them from left to right you can tell windows where the monitors are physically setup from each other. This way your mouse moves off the screen the right direction.