Bug 168808 Display text is lost after launching import values dialog
Steps to reproduce: 1.new a parameter; 2.select list box control type; 3.press "Import Values" button to import some values; 4.assign display texts for the imported values; 5.press "Import Values" button to launch import values dialog again; 6.press ok button on dialog; Expected result: The previous assigned display texts are remained. Actual result: The previous display texts are lost.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
* 
	 * @param title
	 *            the title of the dialog
	 */
	public ParameterDialog( String title )
	{
		this( UIUtil.getDefaultShell( ), title );
	}
	/**
	 * Create a new parameter dialog with given title under the specified shell
	 * 
	 * @param parentShell
	 *            the parent shell of the dialog
	 * @param title
	 *            the title of the dialog
	 */
	public ParameterDialog( Shell parentShell, String title )
	{
		super( parentShell, title );
	}
	protected Control createDialogArea( Composite parent )
	{
		Composite composite = (Composite) super.createDialogArea( parent );
		createPropertiesSection( composite );
		createMoreOptionSection( composite );
		UIUtil.bindHelp( parent, IHelpContextIds.PARAMETER_DIALOG_ID );
		return composite;
	}
	private void createPropertiesSection( Composite composite )
	{