Sennheiser EW100 ENG G3 or AZDEN WLX-PRO VHF WIRELESS LAPEL MICROPHONE?

Which one that can work for my Nikon D3100. Note Nikon D3100 dosen't have mic input. But both of those dosen't need a mic input because you apply them in flash place.

please help if i'm right or no. Which one works for nikon d3100

You had better check out the specifications of both those microphones.

Just because a microphone can mount on a cameras hot shoe, does NOT mean that you do not have to have a microphone input jack

You need to consider using an external sound recorder like the $100 Zoom H1 and use the dual sound recording process to record pristine sound. Then in post, sync the pristine sound from the H1 with the crummy sound from the camera. Once synced, then delete the crummy sound

These are both personal mic systems designed to be plugged into a multi-track recorder or mixing desk! So they don't offer anything to actually record on. On top of that the mics supplied with the transmitters are close field - ie designed to pick up a limited area around them. I agree with FotoAce that you would be far better off with a device such as the Zoom H1 if you are looking for a camera mounted option, or the Zoom H2n if you are looking for something to act as a reporters mic (better suround pick-up).

*Other mic solutions are available!