How do I use the existing raw java code in a new Netbeans GUI Builder


I have some existing hand written GUI code that I wrote in a text editor the hard way. It eventually compiled nicely but now I want to use the GUI builder in NetBeans v7.3 to make some extensive improvements. I cannot for the life of me find any information on how I can load/interface my .java file into the NetBeans IDE GUI Builder. Can anyone steer me to a solution or maybe suggest some keywords? Thanks...

Create a Project in NetBeans then Copy those .Java files into your Package. MAke Sure PAckage name is Correct. Now you can run the GUI from NEtbeans without any Issue. But If you want to use the Designer Mode of Netbeans you need to Create the JFRAME from Netbeans toolbox. Else all there will not be any Issue.