visad.TypeException

["Nash'at Ahmad" <nashat@xxxxxxxxxxxxxxxxxxxxxx>]

Hi,

I am trying to write an application using visad which reads a datafile
and displays it in a JInternalFrame. The first time display works fine
but when I clear the internal frame and try to display a second time 
I get the following exception:

visad.TypeException: ScalarType: name already used

Any help would be appreciated. The source files are attached.

Thanks,

Nash'at