Bug 141255 No error for the incompatible parameter value
Steps to reproduce: 1.New a decimal parameter, set the default value to "aaa" 2.Preview the report by "Preview" tab Expected result: Error to say the incompatible parameter value Actual result: Parameter request page keeps poping up till input the decimal value Note: if preview in Web Viewer, error will be thrown out, but no exception description.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
/**
	 * parse paramenters from config file.
	 * 
	 * @param request
	 * @return
	 */
	protected void parseConfigVars( HttpServletRequest request )
	{
		
		String reportConfigName = this.reportDesignName.replaceFirst(
				IBirtConstants.SUFFIX_DESIGN_FILE,
				IBirtConstants.SUFFIX_DESIGN_CONFIG );
		
		SessionHandle sessionHandle = DesignEngine.newSession( ULocale
				.getDefault( ) );
		ReportDesignHandle handle = null;
		try
		{
			this.configMap = new HashMap( );
			
			handle = sessionHandle.openDesign( reportConfigName );
			
			if ( handle != null )
			{
				Iterator paramIr = null;
				if ( parameterList != null )
					paramIr = parameterList.iterator( );
				Iterator configVars = handle.configVariablesIterator( );
				while ( configVars != null && configVars.hasNext( ) )
				{