Dell Inspiron Laptop 1318

I have a laptop Dell 1318 Inspiron.  At the extreme right front corner of the unit, there is an open 'wireless' slot.  There used to be something there.  Someone stole it.  I can't find what part to replace it.  My computer does not do bluetooth now.  I had to buy an external Netgear wireless adapter, which uses a USB port that I could use.  What is the original equipment that goes in the slot?  Is that why my BT is not working. <ADMIN NOTE: Email id removed per privacy policy> Thanks.