How do you make the Chinese Instrument Erhu???

I really really really really REALLY want to learn how to make an Erhu. Its kinda an ignment but i want to make it for my own pleasure too......so if you know how to make an Erhu with really good sound that can play a whole octave....please please let me know. or if you know of a site that teaches you please help! And i would like it to not be that much money to make and not too dificult but if it is, i guess i can bear it. PLEASE AND THANK YOU!