I was served a lawsuit complaint.Should I include written witnesses responses in the answer I submit.

Not enough information is provided about the case, but you really should not attempt to defend the law suit on your own without the assistance of a lawyer. However, to answer your question, it is too soon to file a motion to dismiss. In the Answer to the Complaint, for those allegations that you believe are in correctyou simply state that they are denied, for the allegations that you believe are correct you simply state that they are correction and for the allegations that you believe do not have sufficient information to either deny or accept, you simply so state.  In your answer, you also have to set forth your counterclaims if you have any and in some types of cases, some counterclaim must be included in the Answer or your right to assert them is lost. Again, you really should not proceed on your own.