help in a GUI, basic signal

how can I do that in a GUI interface. for example: I need the user to insert amplitude, frequency and offset so that a Rectangular signal is projected with those parameters that the user defined in the GUI

A = str2double(get(handles.edit1,'String')); %Amplitude

f = str2double(get(handles.edit2,'String')); %Frecuency

phi = str2double(get(handles.edit3,'String')); %offset

phi2= phi*pi/180;

......