For a couple of panels I don't think you are going to get much of a saving in load time unless they have embedded assets. If embedded assets are an issue you could load them as required rather than embedding them, in that case you could have a loader that is triggered prior to the panel being viewed that calls the required assets.
You could also use modules but then you need to consider things like data sharing intermodule communication etc.
I noticed you double posted, that is a bit of a no.no..
Anyway, if you use your panels in states that helps improve display speed as each panel will only be instantiated when the state is displayed.
http://gumbo.flashhub.net/wizard/ source included
the example is a very simple demonstration of using states to display different panels.
If you were truly looking for a speed advantage , you would write your components in ActionScript.
double posting is a mistake.I know the use of states.but in a state only one
can be shown in one time.thats a problem
I don't see the issue with states, as you said only one at a time, but state 1 can have panel 1 state 2 can have panel 1 and panel 2 etc... if you think more in line with a what you wish to display per screen then regard those screens as a state you will find some display loading improvements.
ya,actually i want something like this.
its like a IDE such as Visual studio.There are many panel navigation,files,
on the first loading only few are opened,and a button for hidden panels are
shown.When user click these buttons then only appropriate panel should be
loaded and shown.