function [] = GUI_21()
 % Demonstrate how to get data from one GUI to another (data passing).
 % Creates a GUI with an editbox and a pushbutton.  When the user presses
 % the pushbutton, another GUI pops up with an editbox.  Whatever is in the
 % editbox of the second GUI when the user hits return will be put into the
 % edit box of the first GUI.
 %
 % Suggested exercise:  Alter the code to have the new GUI display whatever
 % text is in the editbox from the first GUI when the new GUI is created.
 % Even more advanced:  Alter the code so that two new GUIs cannot be
 % launched simultaneously by pressing the pushbutton repeatedly.
 %
 %
 % Author:  Matt Fig
 % Date:  7/15/2009
 
S.fh = figure('units','pixels',...
 'position',[500 500 200 130],...
 'menubar','none',...
 'numbertitle','off',...
 'name','GUI_21',...
 'resize','off');
 S.ed = uicontrol('style','edit',...
 'units','pix',...
 'position',[10 60 180 60],...
 'string','Data');
 S.pb = uicontrol('style','pushbutton',...
 'units','pix',...
 'position',[10 20 180 30],...
 'string','Push to Get Data',...
 'callback',{@pb_call,S});
 
function [] = pb_call(varargin)
 % Callback for GUI_21 pushbutton.
 S = varargin{3};  % Get the structure.
 f = figure('units','pixels',...
 'menubar','none',...
 'position',[750 510 200 100]); % Create a new GUI.
 E = uicontrol('style','edit',...
 'units','pixels',...
 'position',[10 20 180 60],...
 'string','Type something, press return.',...
 'callback',{@E_call,varargin{3}});
 uicontrol(E);  % Allow user to simply hit return without typing anything.
 % If user closes GUI_21, close new one as well because it will error when
 % it tries to execute the callback otherwise.
 set(S.fh,'deletefcn',{@fig_delet,f})
 
function [] = E_call(varargin)
 % Callback for secondary GUI editbox.
 S = varargin{3};  % Get the structure.
 set(S.ed,'string',get(gcbo,'string'))  % Set GUI_21 editbox string.
 close(gcbf)  % Close secondary GUI.
 
function [] = fig_delet(varargin)
 % Executes when user closes GUI_21.
 try
 delete(varargin{3})
 catch
 % Do nothing.
 end