Getting the distances from classes in knnclassify

I ve got a test and train set and I want to create a classifier using knnclassify. I using matlab knnclassify class = knnclassify(words, dictionary, 1:20); where matrix words are the test set dictionary the train set and 1:20 my labels. I am wondering how is it possible to get except from the returned class the distance from those classes in the output.