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/ExtendedItem.java
* @param module
	 *            the report design
	 * 
	 * @return an API handle for this element.
	 */
	public ExtendedItemHandle handle( Module module )
	{
		if ( handle == null )
		{
			handle = new ExtendedItemHandle( module, this );
		}
		return (ExtendedItemHandle) handle;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#hasLocalPropertyValues()
	 */
	public boolean hasLocalPropertyValues( )
	{
		if ( super.hasLocalPropertyValues( ) )
			return true;
		return provider.hasLocalPropertyValues( );
	}
	/**
	 * Gets a property value given its definition. This version checks not only
	 * this one object, but also the extended element this item has. That is, it
	 * gets the "local" property value. The property name must also be valid for
	 * this object.
	 *