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
if ( columns[i] != null )
			{
				column.setText( columns[i] );
			}
			column.setWidth( columnWidth[i] );
		}
		valueTable = new TableViewer( table );
		valueTable.setCellEditors( cellEditors );
		valueTable.setColumnProperties( columns );
		valueTable.setContentProvider( contentProvider );
		valueTable.setLabelProvider( labelProvider );
		valueTable.setCellModifier( cellModifier );
		valueTable.setInput( choiceList );
		valueTable.addSelectionChangedListener( new ISelectionChangedListener( ) {
			public void selectionChanged( SelectionChangedEvent event )
			{
				updateTableButtons( );
			}
		} );
		Composite buttonBar = new Composite( tableArea, SWT.NONE );
		buttonBar.setLayout( UIUtil.createGridLayoutWithoutMargin( 4, false ) );
		buttonBar.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		importValue = new Button( buttonBar, SWT.PUSH );
		importValue.setText( BUTTON_LABEL_IMPORT );
		setButtonLayoutData( importValue );
		
		importValue.setEnabled( !inputParameter.getModuleHandle( )
				.getVisibleDataSets( )
				.isEmpty( ) );
		importValue.addSelectionListener( new SelectionAdapter( ) {