Matlab GUI - parameters passing in function used in button callback

I am calling a function encrypt(S,k) in encrypt button callback. I created the GUI using guide.

Here is the code for Encrypt function:

% --- Executes on button press in Encrypt. function Encrypt_Callback(hObject, eventdata, handles) s = get(handles.edit5,'String'); disp(s); %s = 'jyoti'; %plain text need to be stored from the edit box, user input global X; k = 'key'; % to be generated and stored by sender button... X = enc1(s,k); % X stores the cypher text set(handles.textStatus, 'String', X ); guidata(hObject, handles);

But when I pass s= ' any string', the enc1 works and when I try to store and pass the text from edit box, there comes the following errors:

Error in ==> enc1 at 12 if (ischar(s)==0)

??? Output argument "X" (and maybe others) not assigned during call to "C:\Users\Jyoti\Documents\MATLAB\MATLAB\enc1.m>enc1".

Error in ==> gui>Encrypt_Callback at 278 X = enc1(s,k); % X stores the cypher text

Error in ==> gui_mainfcn at 96 feval(varargin{:});

Error in ==> gui at 43 gui_mainfcn(gui_State, varargin{:});

Error in ==> @(hObject,eventdata)gui('Encrypt_Callback',hObject,eventdata,guidata(hObject))

??? Error while evaluating uicontrol Callback

Help!