1,the upstair tell you a best way.
　　2,you can extends jwindow
　　override show() like this:
　　public void show()
　　{
　　super.show();
　　this.requestfocus();
　　}
　　and then add a window listener for
　　the focus lost event:
　　
　　addfocuslistener (new java.awt.event.focusadapter () {
　　public void focuslost (java.awt.event.focusevent evt) {
　　this.tofront();
　　}
　　}
　　);
　　it seems to work for me...
　　
　　3.you can also try to use thread, i recommend this way.
　　/**
　　* call this from class consructor
　　*/
　　public void initialize() {
　　topthread top = new topthread();
　　top.start();
　　}
　　
　　/**
　　* keep jwindow on top (inner class)
　　*/
　　class topthread extends thread {
　　public void run() {
　　while(true) {
　　tofront();
　　/**
　　* let 10 milliseconds for other code to execute
　　*/
　　try {
　　thread.sleep(10);
　　}
　　catch(exception e) {
　　// do what you wanna do
　　}
　　}
　　}
　　}
　　
　　you can see:http://forum.java.sun.com/thread.jsp?forum=57&thread=166992
　　that's some others discuss it.