Bug 146796 Error message pop up if display text contain non-digital char when add next item
Description: In decimal type parameter creation,display type is "list box", Error message pop up if "display text" contain non-digital char when add next item. Steps: 1.Create a new decimal parameter 2.Set display type as "list box" 3.Input one item: value:1, display text:test 4.Input another item: Value:2 Actual result: error message pop up: The display text already exists! Expected result: Input item succussfully.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
private static final String BOOLEAN_TRUE = Messages.getString( "ParameterDialog.Boolean.True" ); 
	private static final String BOOLEAN_FALSE = Messages.getString( "ParameterDialog.Boolean.False" ); 
	private static final String PARAM_CONTROL_LIST = DesignChoiceConstants.PARAM_CONTROL_LIST_BOX
			+ "/List"; 
	private static final String PARAM_CONTROL_COMBO = DesignChoiceConstants.PARAM_CONTROL_LIST_BOX
			+ "/Combo"; 
	private static final String DISPLAY_NAME_CONTROL_LIST = Messages.getString( "ParameterDialog.DisplayLabel.List" ); 
	private static final String DISPLAY_NAME_CONTROL_COMBO = Messages.getString( "ParameterDialog.DisplayLabel.Combo" ); 
	private static final String NONE_DISPLAY_TEXT = Messages.getString( "ParameterDialog.Label.None" ); 
	private static final Image DEFAULT_ICON = ReportPlatformUIImages.getImage( IReportGraphicConstants.ICON_DEFAULT );
	private static final Image ERROR_ICON = ReportPlatformUIImages.getImage( ISharedImages.IMG_OBJS_ERROR_TSK );
	private static final String STANDARD_DATE_TIME_PATTERN = "MM/dd/yyyy hh:mm:ss a"; 	
	private HashMap dirtyProperties = new HashMap( 5 );
	private ArrayList choiceList = new ArrayList( );
	private static IChoiceSet dataType = DesignEngine.getMetaDataDictionary( )
			.getChoiceSet( DesignChoiceConstants.CHOICE_PARAM_TYPE );
	private static IChoiceSet controlType = DesignEngine.getMetaDataDictionary( )
			.getChoiceSet( DesignChoiceConstants.CHOICE_PARAM_CONTROL );
	private ScalarParameterHandle inputParameter;
	private boolean loading = true;
	private static final SelectionChoice dummyChoice = StructureFactory.createSelectionChoice( );
	private Text nameEditor, promptTextEditor, defaultValueEditor,
			helpTextEditor, formatField;
	
	private Label promptMessageLine;
	
	private CLabel errorMessageLine;
	
	private Button allowNull, allowBlank, doNotEcho, isHidden, needSort;