Hi
That Asus has a combination jack for headphones and microphone,you need one of these.
http://www.amazon.co.uk/Startech-com-3-5mm-Headset-Splitter-Adapter/dp/B004SP0WAQ/ref=sr_1_2?ie=UTF8&qid=1410179244&sr=8-2&keywords=2+3pole+jack+to+1+4+pole+jack