here is riddle........... let's c if u have the guts to solve it

u r locked inside a room.... that has two doors... one leads to heaven n the other leads to hell....... and on each door there is a guard...... one speaks nothing but truth mean sach bolta hai aur doosra jhoot...........
u can ask a single question to anyone of them...... to find out who is a liar n who speaks truth as well which door leads to heaven.......
so wat would u ask..???