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/writer/ModuleWriter.java
* 
	 * @param obj
	 *            the ODA element to write
	 * @param extensionIDProp
	 *            the extension ID for ODA properties
	 */
	private void writeOdaExtensionProperties( DesignElement obj,
			String extensionIDProp )
	{
		IElementDefn extDefn = null;
		if ( obj instanceof OdaDataSource )
			extDefn = ( (OdaDataSource) obj ).getExtDefn( );
		else if ( obj instanceof OdaDataSet )
			extDefn = ( (OdaDataSet) obj ).getExtDefn( );
		if ( extDefn == null )
		{
			ODAProvider provider = null;
			if ( obj instanceof OdaDataSource )
				provider = ( (OdaDataSource) obj ).getProvider( );
			if ( obj instanceof OdaDataSet )
				provider = ( (OdaDataSet) obj ).getProvider( );
			if ( provider instanceof OdaDummyProvider )
				writeOdaDummyProperties( obj, provider );
			return;
		}
		List list = extDefn.getLocalProperties( );
		for ( int i = 0; i < list.size( ); i++ )
		{
			PropertyDefn prop = (PropertyDefn) list.get( i );
			if ( extensionIDProp.equals( prop.getName( ) ) )