One of the major comments that we hear about MATLAB is "I don't know how I can use it in my classroom. It is too hard for my students to use." This may be a correct comment - we don't necessarily want the students to construct a model from scratch in MATLAB, but would want them to use a previously prepared model. We can do this using Input and disp statements in a M-file which is run from the MATLAB window. A much better way is to use a Graphical User Interface (GUI) where the student just "fills in the blanks" and all of the MATLAB commands are completely hidden from the student. Creating GUI's in MATLAB Version 5 is significantly easier than in previous versions of the program. In particular, the guide program allows one to easily place controls onto a model and set their properties.