Trying to Calculate Node Displacement for a Truss using matrix

I am trying to calculate the node displacement of a Truss but my code is returning error. 'Unexpected matlab Function' in me for loop. Can Someone help me understand why my code is not working? Thank You

 % Nodal Displacement
  area = 7550 % mm^2
  E = 69 % GPa
  w = 4 % m
  h = 3 % m

K = [1 0 -1 0; 0 0 0 0 ; -1 0 1 0; 0 0 0 0];
J_C = [0 0 ; w 0; w h; 2*w 0;2*w 2*h; 3*w 0; 3*w 3*h; 4*w 0;4*w 2*h; 5*w 0; 5*w h; 6*w 0];
BarC = [1 2; 2 3; 1 3;2 4;3 4; 4 5; 4 6; 5 6; 5 7; 6 7; 6 8; 6 9; 7 9;8 9; 8 10; 8 11; 9 11;10 11; 10 12; 11 12];

for iEL = 1:nEL
    idBeg = BarC(iEL, 1);
    idEnd = BarC(iEL, 2);
    dx = J_C(idEnd,1) - J_C(idBeg, 1);
    dy = J_C(idEnd,2) - J_C(idBeg, 2);
    L = sqrt(dx*dx + dy*dy);
    c = dx/L
    s = dy/L
    K(2*idBeg - 1,2*idBeg - 1) = c^2;
    K(2*idBeg, 2*idBeg) = s^2;
    K(2*idEnd - 1,2*idEnd - 1) = c^2;
    K(2*idEnd, 2*idEnd) = s^2;
    K(2*idEnd - 1,2*idBeg - 1) = c^2;