Bug 147407 Preview the attached report in the web viewer first time and then click the TOC button will cause NPE error
Description: It just can be reprouduced at first time preview. Step to reproduce: 1. please use attach report file 2. preview it in the web viewer 3. click the "Toggle table of contents" button Actual result: As the atteched screenshot shows,There is a NPE error.And if you preview it in the Web viewer again, the phenomenon is disappear.But reopen the eclipse and preview it at first time, it will be occured.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
*/
	public static final String INIT_PARAM_REPORT_DIR = "BIRT_VIEWER_WORKING_FOLDER"; 
	/**
	 * Servlet parameter name that gives the repository location of the image
	 * files.
	 */
	public static final String INIT_PARAM_IMAGE_DIR = "BIRT_VIEWER_IMAGE_DIR"; 
	/**
	 * Servlet parameter name that gives the repository location of the logging
	 * files.
	 */
	public static final String INIT_PARAM_LOG_DIR = "BIRT_VIEWER_LOG_DIR"; 
	/**
	 * Servlet parameter name that gives the logging level.
	 */
	public static final String INIT_PARAM_LOG_LEVEL = "BIRT_VIEWER_LOG_LEVEL"; 
	/**
	 * Servlet parameter name that gives the repository location of the script
	 * files to run reports.
	 */
	public static final String INIT_PARAM_SCRIPTLIB_DIR = "BIRT_VIEWER_SCRIPTLIB_DIR"; 
	/**
	 * Servlet parameter name that determines the search strategy of searching
	 * report resources. True if only search the working folder, otherwise
	 * false.
	 */
	public static final String INIT_PARAM_WORKING_FOLDER_ACCESS_ONLY = "WORKING_FOLDER_ACCESS_ONLY"; 
	/**
	 * Servlet parameter name that gives the absolute resource location
	 * directory.