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
private Button allowNull, allowBlank, doNotEcho, isHidden, needSort;
	
	private Button importValue, changeDefault, changeFormat, createDataSet;
	
	private Button dynamicRadio, staticRadio;
	
	private Combo dataTypeChooser, controlTypeChooser, defaultValueChooser;
	
	private Combo dataSetChooser, columnChooser, displayTextChooser;
	
	private Label previewLabel;
	private TableViewer valueTable;
	private String lastDataType, lastControlType;
	private String formatCategroy, formatPattern;
	private String defaultValue;
	private Composite valueArea;
	private List columnList;
	private IStructuredContentProvider contentProvider = new IStructuredContentProvider( ) {
		public void dispose( )
		{
		}
		public void inputChanged( Viewer viewer, Object oldInput,
				Object newInput )
		{
		}
		public Object[] getElements( Object inputElement )
		{
			ArrayList list = ( (ArrayList) inputElement );
			ArrayList elementsList = (ArrayList) list.clone( );
			return elementsList.toArray( );