im need to write code to get height and time of the fluid in a reservoir, help guys. is my functions wrong?

Code:

% VALUES GIVEN AND ASSUMED
%DIMENSIONS AND OTHER CONSTANS
L=5; %Length of Tube
x=0:.1:5; %Length vector
dx=0.1; % FOR THE DISTANCE
Ao=1; %Cross-Sectional Area of undeformed Tube
n=(L./dx)+1; %number of nodes
Ro=10^3; %Density of Fluid(Kg/m^3)
Co=10^3; %propagation speed in an initially undeformed
kp=2/3*10^9; %Tube law proportionality constant
% BOUNDARY CONDITIONS
u=zeros(1,n); %Initializes velocity vector to zero
uo=-10; %Velocity of withdrawn fluid(SET BY US)
u(1,1)=uo; %Set the initial velocity to the velocity of withdrawn fluid
un=u;
t=0; %Initializing t to zero
dt=0.00005; %STEP SIZE FOR THE TIME
tmax=0.05; %Total duration of simulation
A=ones(1,n); %Initial Tube Area vector
An=A; %INITIAL AREA
eval('A,kp,Ro,Ao,n'); %calling evalc function
i_end=input('Enter 0 for open end or 1 for closed end TUBE: ');
ip=input('Enter 0 for A vs x or 1 for u vs x: '); % Graphic preference
GRAPHICS(x,A,u,ip,t) %calling graphics function
while t<tmax
%clearing variables
Co=Cn;
uo=un;
Ao=An;
DUA=0;
Cn=c;
while 1
B=zeros((2.*n),1);
M=zeros((2.*n),4);
sol=zeros(1,(2.*n));
[M,B]=setUA(dx,dt,n,i_end,Co,Ao,Cn,un,An)
dUA=solveUA(M,B)
for i=1:n
dU=dUA(i,2*i+1);
dA=dUA(i,2*i);
un=uo+dU;
An=Ao+dA;
end
c=evalc(An,kp,Ro,Ao);
if max(abs(dUA-DUA))<5*10^-6,break,end
DUA=dUA;
end
t=t+dt;
i_end=input('Enter 0 for open end scenario or 1 for closed end scenario: ');
ip=input('Enter 0 for A vs x or 1 for U vs x: ');
GRPHCS(x,A,U,ip,t)
end