Training using Matlab face detector or voila jones algorithm.

Greeting....I have been trying to train the model using matlab's face detector.....but i have not been able to achieve anything. I see that in you loadsamples.m you have given an option for using cascade classifier but some how i cant understand how to use it. Also I coudnt understand the difference between data{}.bbox_gt and data{}.bbox_facedet.

Thank you in advance .