Bug 153391 Some Options in Edit Parameter dialog haven't been saved.
Description: Some Options in Edit Parameter dialog haven't been saved. Steps to reproduce: 1. new a parameter, boolean type, tick AllowNUll and sort alphabetically... 2. Close the dialog and reopen it. 3. new a parameter, string, combo-box, tick AllowNull. 4. Close the dialog and reopen it. Expected result: Ticked options' status are saved Actual result: After reopen parameter dialog, options are unticked.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
return choiceSet;
	}
	private void updateFormatField( )
	{
		String displayFormat;
		String previewString;
		String type = getSelectedDataType( );
		IChoiceSet choiceSet = getFormatChoiceSet( type );
		if ( choiceSet == null )
		{
			displayFormat = DEUtil.getMetaDataDictionary( )
					.getChoiceSet( DesignChoiceConstants.CHOICE_STRING_FORMAT_TYPE )
					.findChoice( DesignChoiceConstants.STRING_FORMAT_TYPE_UNFORMATTED )
					.getDisplayName( );
			previewString = "True"; 
		}
		else
		{
			displayFormat = choiceSet.findChoice( formatCategroy )
					.getDisplayName( );
			if ( defaultValue != null )
			{
				previewString = format( defaultValue );
			}
			else
			{
				if ( formatCategroy == DesignChoiceConstants.STRING_FORMAT_TYPE_CUSTOM
						|| formatCategroy == DesignChoiceConstants.NUMBER_FORMAT_TYPE_CUSTOM
						|| formatCategroy == DesignChoiceConstants.DATETIEM_FORMAT_TYPE_CUSTOM )
				{