Bug 213680 [2.2.2]Chart script can not be cleaned completely.
Description: Reset script or delete all script does not work. build version: v20071221-0630 steps to reproduce: 1. New a report. 2. New a chart. 3. Enter some script for the chart and save the report. 4. Click the reset scirpt button or delete all script. 5. Save the report and switch to layout,then switch back to script page. Expected result: Script are cleaned. Actual result: Script are not cleaned. Note: If you delete part of the script, it works.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/elements/strategy/ExtendedItemPropSearchStrategy.java
if ( value != null )
			return value;
		
		String selector = ( (ElementDefn) extendedItem.getDefaultDefn( ) )
				.getSelector( );
		return getPropertyFromSelector( module, prop, selector );
	}
	/**
	 * Gets the property value from some predefined-styles in this extended
	 * item. Such as x-tab header, x-tab footer.
	 * 
	 * @param module
	 * @param extendedItem
	 * @param prop
	 * @return
	 */
	private Object getPropertyFromPredefinedStyles( Module module,
			ExtendedItem extendedItem, ElementPropertyDefn prop )
	{
		List predefinedStyles = extendedItem
				.getReportItemDefinedSelectors( module );
		if ( predefinedStyles == null || predefinedStyles.isEmpty( ) )
			return null;
		for ( int i = 0; i < predefinedStyles.size( ); i++ )
		{
			Object predefinedStyle = predefinedStyles.get( i );
			
			
			if ( predefinedStyle instanceof String )
			{