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
}
	private String getInputDisplayName( )
	{
		String displayName = null;
		if ( DesignChoiceConstants.PARAM_CONTROL_LIST_BOX.equals( selectedParameter.getControlType( ) ) )
		{
			if ( selectedParameter.isMustMatch( ) )
			{
				
				displayName = DISPLAY_NAME_CONTROL_LIST;
			}
			else
			{
				
				displayName = DISPLAY_NAME_CONTROL_COMBO;
			}
		}
		return displayName;
	}
	private IChoiceSet getFormatChoiceSet( String type )
	{
		IChoiceSet choiceSet = null;
		if ( DesignChoiceConstants.PARAM_TYPE_STRING.equals( type ) )
		{
			choiceSet = DEUtil.getMetaDataDictionary( )
					.getChoiceSet( DesignChoiceConstants.CHOICE_STRING_FORMAT_TYPE );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DATETIME.equals( type ) )
		{
			choiceSet = DEUtil.getMetaDataDictionary( )