Even if you don't have any recollection of it you still dream every night. To aid in recall you might try some autosuggestion. While you are falling asleep repeat something in your head such as "I will remember all of my dreams". It doesn't have to be specifically that, it can be what ever you like.
Here is the tutorial on dream recall.
http://www.dreamviews.com/community/...ad.php?t=66343
Here is the section of the forum dedicated to dream signs and recall.
http://www.dreamviews.com/community/...splay.php?f=15
If you have any more questions please do not hesitate to ask.