H form

I have purchased packing material against h form, now I have h form. but the problem is that I don't know how to fill the form. or m I supposed to give the h form to seller. and what proof should I take as an acknowledgement from the seller that I have issued a h form to him. and h form is issued for a quarter or for a year. and the date of issue on h form is 9/12/13 and the purchase is of the period 12-13 , will it make a difference or not. Help in this regard will be highly appreciated. Regards Fazil Ahmad