Chinese PHP contact form fix

I have a php driven contact form that is hosted on a chinese site. When Chinese text is inputed to the contact form, it sends back an email with unrecognizable characters. I know nothing about chinese characters, and just populated a second version of the english site with Chinese translations I was given. I need someone who can test and edit the code for my form so the form email will display the chinese characters as they are entered in the submit form. I have attached the header, contact form, and send function, and just need to know how I need to set up the encoding, if that is the problem.