stupid question...

OKay…i modeled a bottle in blender…i gave it some thickness…then i have it a glass material in yafaray…but in comes out looking all weird…im not sure if im modeling the glass wrong omy settings are wrong…but im not sure whats wrong…it come out all distorted on the edges with black spots…it looks weird…any help or a good tutorial would help

First, check for doubles. Any double vert or face may cause a lot of problems.
Second thing to check would be your face normals. They have to point outwards. Ctrl N is your friend.
Third, check the yafaray settings for rendering. Read the instructions at