bool ControlPanel::CanClose( void )
{
	workspacefiles->StartStoringFiles( IWorkspaceFiles::EXPRESSION );
	for ( int i = 0 ; i < expressions->GetNumClasses(); i++ )
	{
		CExpClass *cl = expressions->GetClass( i );
		if ( cl )
		{
			workspacefiles->StoreFile( IWorkspaceFiles::EXPRESSION, cl->GetFileName() );
		}
	}
	workspacefiles->FinishStoringFiles( IWorkspaceFiles::EXPRESSION );
	// Now close them all, or abort exit if user doesn't want to close any that have changed
	return Closeall();
}