Fixed grammar

docs/docs/howto_contribute.xml

@@ -252,7 +252,7 @@ Then <a href="mailto:davis@dlib.net">email me</a> the dlibchanges.hg file and I'
                   shown in <a href="sockets_ex_2.cpp.html">this</a> example program.
                </p>
                <p>
-                  RAII is a trivial technique to use.  All you have to do is not call new and delete yourself and
+                  RAII is a trivial technique to use.  All you have to do is not call new and delete and
                   you will never have another memory leak.  Just use the appropriate <a href="containers.html">container</a>
                   instead.  Finally, if you don't use RAII then your code is almost certainly not exception safe.   
                </p>