Bug 180864 Change Allow Null option in Cascading Group.[0705]
Description: Change Allow Null option in Cascading Group. Build number:2.2.0.v20070404 Steps to reproduce: 1. New a cascading group and add sub parameter. Expected result: Is Required option in cascading group definition dialog. Actual result: Allow null value option in Cascading Group definition dialog Error log:N/A
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/CascadingParametersDialog.java
setControlEnabled( false );
			return;
		}
		loading = true;
		setControlEnabled( true );
		paramNameEditor.setText( selectedParameter.getName( ) );
		if ( selectedParameter.getPromptText( ) == null )
		{
			promptText.setText( "" ); 
		}
		else
		{
			promptText.setText( selectedParameter.getPromptText( ) );
		}
		dataTypeChooser.setText( DATA_TYPE_CHOICE_SET.findChoice( selectedParameter.getDataType( ) )
				.getDisplayName( ) );
		if ( getInputDisplayName( ) == null )
		{
			displayTypeChooser.clearSelection( ); 
		}
		else
		{
			displayTypeChooser.setText( getInputDisplayName( ) );
		}
		defaultValue = selectedParameter.getDefaultValue( );
		if ( defaultValue == null )
		{
			defaultValueEditor.setText( "" ); 			
		}
		else