Hi bothers , I have a big problem ! sincerly I am beginner in solidworks API .so I have not much idea and experience with API and VBA;  if you remember today I asked you about the method to calculate the dot product of two palar face. my problem is that I have two palanar faces in contact ( coincident mate inially) ! After I tried to rotate the face of one of the two plar face. so in this case the coincident mate does not exist and there are an error in assembly mates. I need to write a macro to replace coincident mate inially between face -face by another like for example coincident FACE-EDGE or coincident FACE -VERTEX based on the new oriantation of the twho faces. how can I know that the FACE -FACE mate will be for example FACE-EDGE mate or FACE-VERTEX late ! . thanks in advance