Handles error while using rcvTools in robotics.

hello

every time i run this code so many errors message pop-up

the code is :

theta1=str2double(handles.theta1.string)*pi/180;
theta2=str2double(handles.theta2.string)*pi/180;
theta3=str2double(handles.theta3.string)*pi/180;
L1=0;
L2=0;
L3=0;
L(1)=Link([0 L1 0 0]);
L(2)=Link([0 L2 0 -pi/2]);
L(3)=Link([0 L3 0 0]);

robot=SerialLink(L)
rbot.name='wissam sami';
robot.polt([theta1 ththeta2 theta3])
T=robot.fkine([theta1 theta2 theta3])
handles.pos-x.string=num2str(floor(T(1,4)));
handles.pos-y.string=num2str(floor(T(2,4)));
handles.pos-z.string=num2str(floor(T(3,4)));
% --- Executes on button press in btn_Invers.
function btn_Invers_Callback(hObject, eventdata, handles)
% hObject    handle to btn_Invers (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
PX=str3double(handles.pos-x.string)
PY=str3double(handles.pos-y.string)
PZ=str3double(handles.pos-z.string)
L1=20;
L2=50;
L3=40;
L(1)=Link([0 L1 0 0]);
L(2)=Link([0 L2 0 -pi/2]);
L(3)=Link([0 L3 0 0]);
robot=SerialLink(L)
rbot.name='wissam sami';
TI=[1 0 0 PX;
    0 1 0 PY;
    0 0 0 PZ;
    0 0 0 1]
J=robot.ikine(Ti,[0 0 0], [1 1 1 0 0 0])*180/pi;
    handles.theta1.string=num2str(floor(J(1)));
     handles.theta2.string=num2str(floor(J(2)));
      handles.theta3.string=num2str(floor(J(3)));
      robot.plot(J*pi/180);
      

help please.