I accidentaly I clicked on "forget this conection"

Hi!
The problem is as the title says. I wanted to get conected to intenrnet but due to the fact that my wireless conection was very weak i could not conect. After that, appeared an option which said "forget this conextion" and accidentally clicked on it,
and now i can not see my own internet conextion. What can i do to see my conection again???????

Thankyou!!!!!