Question: procedure error end p^loting 2d

please please help meeeeeeeeeeeeeeee

> restart;

> Ndx := 6; Ndy := 3; imax := Ndx+1; jmax := Ndy+1; Tb := 0; Td := 60; Th := 180; Tg := 80;
                                                                      
> Ndeq := (imax-2)*(jmax-2);
                                    
> with(GraphTheory);

with(SpecialGraphs);
> G := GridGraph(imax, jmax);
 
> IsBipartite(G); DrawGraph(G);
> for i to imax do T[i, 1] := Tb end do;

> for i to imax do T[i, jmax] := Th end do;
                                    
> for j to jmax do T[1, j] := Tg end do;
                                    
> for j to jmax do T[imax, j] := Td end do;
                                   
> k := 1;
                                
>
> for j from 2 to Ndy do for i from 2 to Ndx do Eq[k] := -4*T[i, j]+T[i-1, j]+T[i+1, j]+T[i, j-1]+T[i, j+1] = 0; var[k] := T[i, j]; k := k+1 end do end do;
>
> for k to Ndeq do Eq[k]; var[k] end do;
> with(LinearAlgebra);
> sys := [seq(Eq[k], k = 1 .. Ndeq)];
         
> var := [seq(var[k], k = 1 .. Ndeq)];

  > A, B := GenerateMatrix(sys, var);
  > Ainvers := MatrixInverse(A);
 > T := MatrixVectorMultiply(Ainvers, B);
> evalf(T);

>