Bug 146159 [Regression]Changing font operation doesn't work other than the first time
Description: The first time changing operation can work well. However, Change it again, it won't work. Steps: 1.Insert lable/text to layout or master page 2.Change the font from serif to cursive, it works well 3.Change the font again Result: The action doesn't work Additional infor: build number:200606080632
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
public static int findPos( DesignElementHandle parent, int slotID,
			DesignElementHandle child )
	{
		assert slotID >= 0;
		SlotHandle slotHandle = parent.getSlot( slotID );
		return slotHandle.findPosn( child );
	}
	/**
	 * Gets the element name. The object is a long string that separated with
	 * the separator "."
	 * 
	 * @param obj
	 *            the object
	 * @return the name behind the last separator "."
	 */
	public static String getElementName( Object obj )
	{
		if ( obj instanceof Class )
		{
			obj = ( (Class) obj ).getName( );
		}
		return obj.toString( ).substring(
				obj.toString( ).lastIndexOf( "." ) + 1 ); 
	}
	/**
	 * Gets the definition for the element with the specified name
	 * 
	 * @param elementName
	 *            the name of the element
	 *