Bug 155751 [regression]Nothing displayed when drag report items from a old library to a report layout
Nothing displayed when drag report items from a old library to a report layout Steps to reproduce: 1.new a report and use a old library in outline view 2.Drag table,label,text,chart all to the report layout 3.Nothing displayed when previewed Expected result: Items can be diplayed properly' Actual result: Items weren't displayed when drag report items from a old library to a report layout while displayed well when drag report items from a new library to a report layout
viewer/org.eclipse.birt.report.viewer/src/org/eclipse/birt/report/viewer/utilities/WebViewer.java
* HTML format name
	 */
	final public static String HTML = "html"; 
	/**
	 * PDF format name
	 */
	final public static String PDF = "pdf"; 
	/**
	 * Birt web viewer plugin id
	 */
	final public static String WebAppPlugin = ViewerPlugin.PLUGIN_ID;
	/**
	 * locale preference name
	 */
	final public static String USER_LOCALE = "user_locale"; 
	/**
	 * Preference key for SVG chart flag.
	 */
	final public static String SVG_FLAG = "svg_flag"; 
	/**
	 * Preference key for master page content flag.
	 */
	final public static String MASTER_PAGE_CONTENT = "master_page_content"; 
	
	final public static String PREVIEW_MAXROW = "preview_maxrow"; 
	
	/**
	 * Key to indicate the format of the preview.
	 */
	public final static String FORMAT_KEY = "FORMAT_KEY";