How do I plot the trajectory?

I'm not sure why it woudn't plot.

clc;clear
%Before Impact
%Horizontal direction
Sx=2.8;                     %the distance before impact
So=0;                       %the initial distance
V=10;                       %velocity it threw 
Vx=V*cosd(20)               %velocity in x direction
Voy=V*sind(20)              %velocity in y direction 
a=9.81;                     %acceleration of gravity
Soy=1.3;                    
e=.88;                      %coefficienet of restitution 
t=(Sx+So)/Vx                    
% Vertical Direction
Vy=Voy-a*t                  %velcoity before impact
%During Impact
%The point where the ball will hit the wall vertically
Sy=Soy+Voy*t-.5*a*t^2
%Magnitude of the velocity
Vb1=sqrt(Vx.^2+Vy.^2)               %velocity when it hit the wall 
Theta=atand(Vy/Vx)                  % the angle it went
%Conservation of Momentum in Y_direction
Vb2sinbeta=Vy                       
Vb2cosbeta=e*Vx
Beta=atand(Vb2sinbeta/Vb2cosbeta) 
%Velocty at with the ball bounce back from the wall
Vb2= Vb2cosbeta/(cosd(Beta))
% After the Impact
a=.5*a
b=-Vb2*(sind(Beta))
c=-Sy
x1=(-b+sqrt(b.^2-4.*a.*c))/(2.*a)
x2=(-b-sqrt(b.^2-4.*a.*c))/(2.*a)
if (x1 >=0)
S= So+Vb2*cosd(Beta)*x1
else
    S= So+Vb2*cosd(Beta)*x2
end

%plot of the trajectory

x= Sx+Vb2*cosd(Beta)*x1
y=Soy+Vy*t+.5*a*t.^2
plot(x,y)
hold on
xx=(0:.88:5.56)
y1=S
plot(xx,y1,xlim,[0,0])
xlabel('Horizontal Distance')
ylabel('velocity the ball travelling')

[Image Analyst]

When you do this to reassign x with a new x:

x= Sx+Vb2*cosd(Beta)*x

what is the original x when you get to that point? It's saying it's undefined.

[abraj ali]

actually i meant x1for time*x