Bug 176681 Issue about creating context-parameter path in read-only path[0601]
Description: Issue about creating context-parameter path in read-only path Build number:2.2.0.v20070308 Steps to reproduce: 1. Deploy birt. 2. Set BIRT_VIEWER_DOCUMENT_FOLDER/BIRT_VIEWER_IMAGE_DIR/.. to a read-only path. 3. Preview report. Expected result: Because the path is read-only, folders should be created in ${java.io.tmpdir} Actual result: No folders are created in ${java.io.tmpdir} and reports cannot be previewed in frameset mode.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
* @param paramName
	 *            String
	 * 
	 * @return String
	 */
	public static String getFormat( HttpServletRequest request, String paramName )
	{
		if ( request == null || paramName == null )
			return null;
		return getParameter( request, paramName + "_format" ); 
	}
	/**
	 * @return the isWorkingFolderAccessOnly
	 */
	public static boolean isWorkingFolderAccessOnly( )
	{
		return isWorkingFolderAccessOnly;
	}
	/**
	 * if display text of select parameter
	 * 
	 * @param paramName
	 * @return
	 */
	public static String isDisplayText( String paramName )
	{
		if ( paramName == null )
			return null;
		if ( paramName.startsWith( PREFIX_DISPLAY_TEXT ) )
		{