To extract the data (text) from the edit box, you will need something more or less like this:
% Get the string from the editText box.
myText = get(S.ed, 'String');
EDIT
When you run a GUI, the variables' scope is only within the GUI. If you want to be able to manipulate that variable later, save the variable into a .mat file and load it later. For example:
% Get the string.
myText = get(S.ed, 'String');
% Save the variable into a .mat file.
save('myTextVariable', 'myText');
Later, to recover it:
% Load the variable for later use.
load('myTextVariable', 'myText');
Try it and let me know if it works ;-)
