Question: Please need help with my proc

Please I need help with my proc.

> RK2skritt:=proc(FR::procedure,xo,yo,vxo,vyo,h) local x, y, vx, vy, r, kx1, kx2, kx3, kx4, ky1, ky2, ky3, ky4, l x1, l x2, l x3, l x4, ly1, ly2, ly3, ly4, tmp; r:=sqrt(xo*xo+yo*yo); tmp:=-(h*FR(r))/(r); lx1:=h*vxo; ly1:=h*vyo; kx1:=tmp*xo; ky1:=tmp*yo; lx2:=h*(vxo+0.5*kx1); ly2:=h*(vyo+0.5 ky1); r:=sqrt((xo+0.5*lx1)^(2)+(yo+0.5*ly1)^(2)); tmp:=-(h*FR(r))/(r); kx2:=tmp*(xo+0.5*lx1); ky2:=tmp*(yo+0.5*ly1); lx3:=h*(vxo+0.5*kx2); ly3:=h*(vyo+0.5*ky2); r:=sqrt((xo+0.5*lx2)^(2)+(yo+0.5*ly2)^(2)); tmp:=-(h*FR(r))/(r); kx3:=tmp*(xo+0.5*lx2); ky3:=tmp*(yo+0.5*ly2); lx4:=h*(vxo+kx3); ly4:=h*(vyo+ky3); r:=sqrt((xo+lx3)^(2)+(yo+ly3)^(2)); tmp:=-(h*FR(r))/(r); kx4:=tmp*(xo+lx3); ky4:=tmp(yo+ly3); x:=xo+(lx1+2*lx2+2*lx3+lx4)/(6); y:=yo+(ly1+2*ly2+2*ly3+ly4)/(6); vx:=vxo+(kx1+2*kx2+2*kx3+kx4)/(6); vy:=vyo+(ky1+2*ky2+2*ky3+ky4)/(6); [x,y,vx,vy]; end proc: Error, invalid local declaration Please someone help me!!!!!!!!