What is an "element", you mean a "uiobject" (uibutton, uitable etc?)?
Happy to help, but you'll have to work on the question clarity a little for me.
Do you want to create uicontrols programmatically when certain values are selected in other uicontrols?
In this case you'll need to put uicontrol() commands inside the callbacks of your "parent"/controlling uiobjects.
-------------------------------------------------------------------
I'm afraid I can't describe the entire process of GUI-design here (which is really what your question requires) so it will be a case of doing a lot of background reading on your, unless you have a very specific task you want to achieve.
Broadly, your options are 1) use GUIDE to drag & drop objects into a figure 2) use the uicontrol() to generate uiobjects in a figure programmatically
In both cases you will then put code into the callbacks which changes the properties of the objects (the values in textboxes) when events are triggered (i.e. the user pushes a button)
If you want to make a group of objects appear & disappear then create them inside a uipanel (their parent should be the panel) and make the panel visible/invisible by
set(handles.myPanel,'visible,'off')
You can put this command inside the callback of a pushbutton (for example) to facilitate control of the panel.
I'd suggest that you play around with this stuff a little and come back to the Matlab Answers if you hit a specific hurdle along the way.
