Function what draws 2d rectangle.

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    function rectangle(left,top,right,bottom)
 line left,top,right,top
 line right,top,right,bottom
 line right,bottom,left,bottom
 line left,bottom,left,top
endfunction