This not a Netbeans forum.
However, to do this, Go to File > New File
From the dialog, choose one of the standard Netbeans Forms to start with to create a GUI form with the necessary source code
You can cannot create a GUI from your existing code or classes. You'd have to start a GUI from scratch using netbeans
You can also search the net, and MOST ESPECIALLY, check the Netbeans Application HELP. This should always be your first line of action before posting on these forums
ICE