Bug 136770 Cannot view report document from web viewer
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";