Question: Numerical solution of ODE

Hi everyone, im trying to solve the following system of ode (motion of a double pendulum) where im trying to plot numerical solution for T1(t) and T2(t). Been searching for a while... found nothing :) Here is my code , i also loaded the library plots, DEtools. . Im using maple 15

> Systeme := [2*(diff(T1(t), x, x))+cos(T1(t)-T2(t))*(diff(T2(t), x, x))+sin(T1(t)-T2(t))*(diff(T2(t), x))^2+19.6*sin(T1(t)) = 0, diff(T2(t), x, x)+cos(T1(t)-T2(t))*(diff(T1(t), x, x))-sin(T1(t)-T2(t))*(diff(T1(t), x))+9.8*sin(T2(t)) = 0, T1(0) = 1, (D(T1))(0) = 1, T2(0) = 1, (D(T2))(0) = 1]:

     > sol:=dsolve(Systeme,type=numeric):

sol:=proc(rkf45_t)end:

plots[odeplot](sol,[t,T1(t)],[t,T2(t)],0..20);

Error code: Error, (in plots/odeplot) invalid input: member expects 2 or 3 arguments, but received 1

Whats wrong??????? Thanks