Error using get There is no string property on the Root class

In case it helps, I am trying to write a code using user input. The user inputs data into two edit boxes, an X and a Y. The coordinates are then to be stored into the table when the push button is clicked on. Any reference is accepted. Thank for the help.

Error using get                                   %   The error message
There is no string property on the Root class     %
XData = get(handles.X_coord, 'string');   % That is the error is occuring


% THe follwoing is what I have written with reference to some videos on youtube

% --- Executes just before Truss_ANA is made visible.
function Truss_ANA_OpeningFcn(hObject, eventdata, handles, varargin)

global p
p.Table_coord = [];

handles.output = hObject;
guidata(hObject, handles);

handles.output = hObject;
guidata(hObject, handles);

function X_coord_Callback(hObject, eventdata, handles)
handles.X_coord = str2double(get(hObject,'string'));
guidata(hObject, handles);

function Y_coord_Callback(hObject, eventdata, handles)
handles.Y_coord = str2double(get(hObject,'String'));
guidata(hObject, handles);

% --- Executes on button press in Coord_button.
function Coord_button_Callback(hObject, eventdata, handles)


 x_coord = handles.X_coord;
 y_coord = handles.Y_coord;
 
axis([0, max(x_coord)+1, 0, max(y_coord)+1])
trussmember = line(x_coord,y_coord,'Marker','.','LineStyle','-');
set(trussmember,'Color','red')

 global p 

XData = get(handles.X_coord, 'string');
YData = get(handles.Y_coord, 'string');

p.Table_coord = [p.Table_coord; [{XData} {XData}]];

set(handles.Table_coord, 'Data', p.Table_coord)


% The portion in the comments is another version of what I am trying to do 

%x={handles.X_coord};
%y={handles.Y_coord};

%data = get(handles.Table_coord,'data');

%for i = 1:handles.deg_free
%      x={handles.X_coord};
%      y={handles.Y_coord};
%      data= set(handles.Table_coord,'data');

%data{end,i} = data{end,x};
%data{end+1,i} = data{end+1,y};

%set(handles.Table_coord, 'data',data)
     % t.data = get(handles.Table_coord, 'data');
      %data = [x;y];
      %guidata(hObject,handles);
%end 



%disp(data)

handles.output = hObject;
guidata(hObject, handles);
set(handles.Table_coord,'Data',data);
guidata(hObject,handles);

hold on