do you know what i mean. it is a symbol where i can see all W-LANs.
Following on from HippyTaff's answer, if the questions is more the former (I'll assume you have an icon - *but* it's not displaying a list of available WiFi signals to connect too), then we'd have to assume there are issues with your WiFi / wireless network card.
There's some information on the wiki Networking / WiFi FAQ to assist with this. If all else fails - follow the instructions in the link detailing on how to gather more information (about your networking hardware) and post it back into this thread and we'll try to help you further.