problems with dht22

hello there

I tried to communicate with a dht 22.

after decration of #include <DHT.h>

I get error

C:\Users\homylabs\AppData\Local\Temp\cclIUl0U.ltrans0.ltrans.o: In function `__static_initialization_and_destruction_0’:

D:\develop\arduino\vochtsensor\arduino uno\vochtregelaar_V1_00/vochtregelaar_V1_00.ino:8: undefined reference to `DHT::DHT(unsigned char, unsigned char, unsigned char)’

is it possible that I have the wrong DHT.H header?

thanks in advance

Jos