How to open existing project with NetBean6.1

Hi All, we have 1 project which is done using NetBean6.1 platform.The problem that we are facing now is we are not able to open the project as a whole.We only manage to open it file by file only.But the thing is the files are referring to each other and hence the program is not executable.
We have perform a basic screening on the project and  below is our finding:

(a).There are form such as FwLoaderAboutBox.form and FwLoaderAboutBox.java.
(b).There is a org.jdesktop.application in the project which is in the folder META-INF\services.
(c).  There are a lot of file ending with .java in models folder.

We have try to open the via File->open project but to our effort there is no way to add the project to NtBean6.1

Can anyone advise?