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
{
					previewString = new NumberFormatter( isCustom( ) ? formatPattern
							: formatCategroy,
							ULocale.getDefault( ) ).format( 1234567890 );
				}
				else
				{
					previewString = new NumberFormatter( isCustom( ) ? formatPattern
							: formatCategroy,
							ULocale.getDefault( ) ).format( 123456789.01234 );
				}
			}
		}
		formatField.setText( displayFormat );
		previewLabel.setText( convertNullString( previewString ) );
		changeFormat.setEnabled( choiceSet != null );
	}
	private String convertNullString( String str )
	{
		if ( str == null )
		{
			return "";
		}
		return str;
	}
	private boolean containValue( SelectionChoice selectedChoice,
			String newValue, String property )
	{
		for ( Iterator iter = choiceList.iterator( ); iter.hasNext( ); )
		{