oop - How to change orientation of robot in c# -

i have class called baserobot, following code

{    //=== defines possible orientation of robot. //=== note order important allow cycling performed in meaningful manner. public enum compass {     north, east, south, west };  //=== basic robot. public class baserobot {     //--- behaviour properties identified, associated state.     //--- robot identification number.    private int mid;    public int id    {        { return mid; }    }     //--- direction in robot facing.    private compass morientation;    public compass orientation    {        { return morientation; }        set { morientation = value; }    }     //--- robot's current position.    private point mposition;    public point position    {        { return mposition; }    }      //--- robot's home position, created.    public point mhome;    public point home    {        { return mhome; }    }      //--- turn orientation left (anti-clockwise) or right (clockwise).     //--- implementation relies on n, e, s, w ordering of enumeration values allow arithmetic work.      public void turnleft()     {         --morientation;         if (morientation < 0) morientation = compass.west;     } // end turnleft method.          public void turnright()     {         morientation = (compass)(((int)morientation + 1) % 4);     } // end turnright method.      //--- move 1 unit forward in current orientation.     public void move()     {         switch (morientation)         {             case compass.north: mposition.y++; break;             case compass.east: mposition.x++; break;             case compass.south: mposition.y--; break;             case compass.west: mposition.x--; break;         }     } // end move method.      //--- constructor methods.     public baserobot(int aid)     {         mid = aid;         mhome.x = 0;         mhome = new point(0, 0);         mposition = mhome;     }     public baserobot(int aid, int ax, int ay)     {         mid = aid;         mhome = new point(ax, ay);         mposition = mhome;     } // end baserobot constructor methods.    } // end baserobot class.  } // end namespace. 

in main program class have this

  //calling  baserobot constructors          var robot1 = new baserobot(0);         var robot2 = new baserobot(0,0,0);          console.writeline("===defualt robot===");         stringbuilder db = new stringbuilder();         db.appendformat("robot#1 has home @ <{0},{0}>. ", robot1.home.x, robot1.home.y);         db.appendformat("it facing {0} ", robot1.orientation);         db.appendformat("and @ <{0},{0}>.", robot1.position.x, robot1.position.y);         console.writeline(db.tostring()); 

this works fine wondering how change way robot facing south, east , west? when change home coordinates of robot (35,12), unhandled error message saying index (zero based) must greater or equal 0 , less size of argument list.

the turnleft , turnright methods rotate robot modifying morientation field , since have provided setter property can change direction directly by:

robot.orientation = compass.west;