Nobody can help me ?

Below I posted equations in text mode, maybe someone will look at this, and telling me what am l doing wrong:

eqns:=[diff(x(t),t)=-x(t)-y(t),diff(y(t),t)=x(t)+0.25*y(t)+r(t),diff(z(t),t)=3+x(t)*z(t),diff(r(t),t)=0.5*z(t)+0.05*r(t)];

And draw 3DPlot:

DEplot3d(eqns,{x(t),y(t),z(t),r(t)},t=0..300, [[x(0)=0,y(0)=0,z(0)=0,r(0)=0]], x=-20..15, y=-20..15, z=-20..25, r=-20..25, stepsize=0.05, linecolour=1+sin(t*PI/3)/2, thickness=1, orientation=[-110, 71],scene=[x(t),y(t),z(t)]);

thanks for any help...