I typed the following code in a new .nb :

enneper[u_, v_] := {u - u^3/3 + u v^2, -v + v^3/3 - v u^2, u^2 - v^2} 
zz:= ParametricPlot3D[enneper[u,v], {u,-2,2}, {v,-2,2}, 
       PlotPoints->{20,20}]
    S @ Shadow[zz, ZShadow->False];

because I want to obtain something like this: I don't know why after Running Mathematica return the following errors: Show::gtype: Shadow is not a type of graphics (1 for enneper), Export::obsalt: Display is obsolete. Instead, use Export, Export::noopen: "Cannot open \!(\"stdout\") (2 for the catalan). The Catalan surface has the following code:

catalan[a_][u_,v_]:= 
   {a(u-Sin[u]Cosh[v]), a(1-Cos[u]Cosh[v]), -4a Sin[u/2]Sinh[v/2]}
Module[{x,\[Alpha]},
   x= catalan[1];
   \[Alpha][u_]= x[u,0];
   z1= ParametricPlot3D[Append[x[u,v],
      FaceForm[Yellow,Orange]], {u,2\[Pi],6\[Pi]},{v,-2,2}, 
      Lighting->False, PlotPoints->{40,20}];
   z2= ParametricPlot3D[highlight[\[Alpha],.6][u],{u,0,10\[Pi]}];
   S[z1,z2]
];   

and the final results should be How can I fix this errors? It has been over 2 days since I begun to fix this ones. It would help me another possible commands.