Can i use the externalflash (SB 700) on the Nikon D5200 wireless?

I remember the Nikon D80 that you can use the external flash wireless. Does Nikon DSLR cameras still have that function to do that especially on the D5200?

No - it doesn't have the Nikon AWL/CLS system that allows the pop-up flash to act as a commander for setting flash power and triggering the flash off camera.

You can of course, put the SB700 into optical slave mode, set the power on it manually and still use the pop-up flash on the D5200 as an optical trigger, but it won't have the onboard control of the external flash.

If you don't want to rely on optical triggering, then get a set of RF602 radio triggers - you will need to have the SB700 and your D5200 both in manual mode. Again, you'd set the flash power manually on the SB700.

The entry level NIkon DSLRs (D3xxx and D5xxx) do not have this function. The up-scale DSLRs (D7000, etc) still do.

You need to buy either a SU800 or 3rd party TTL transceivers (Pocket Wizards or Yongnuo TTL) to have full control over a wireless flash. The SU800 is equivalent to the part that is missing in your camera.

By the way, the SB700 does not have an optical slave feature. You need to buy the SU4 ($85) if you want the SB700 to have an optical slave function - even in manual (or buy 3rd party triggers).