how do آپ invite دوستوں to your town

Well, when آپ invite them from DS to DS, just go to the town door (sry for my english) and chose "open the town door". Then آپ chose "DS to DS". When it has loaded, just wait for your دوستوں coming!
And when آپ want to visit someone, it´s just like this: the friend has to open his town door first. Then آپ go to your town door and chose "I want out" and "DS to DS". It will be shown to آپ which town doors are open. Now chose the town you´d like to visit. That´s it!