Bug 136770 Cannot view report document from web viewer
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
queryString += ( isFirst ? "" : "&" ) + PARAM_ISNULL + "=" + paramName; 
					isFirst = false;
					continue;
				}
				if ( paramName.equalsIgnoreCase( name ) )
				{
					paramValue = value;
				}
				paramName = urlEncode( paramName, "ISO-8859-1" ); 
				paramValue = urlEncode( paramValue, "UTF-8" ); 
				queryString += ( isFirst ? "" : "&" ) + paramName + "=" + paramValue; 
				isFirst = false;
			}
		}
		if ( nullParams != null && nullParams.size( ) > 0 )
		{
			Iterator i = nullParams.iterator( );
			while ( i.hasNext( ) )
			{
				String paramName = (String) i.next( );
				if ( paramName != null && !paramName.equalsIgnoreCase( name ) )
				{
					paramName = urlEncode( paramName, "UTF-8" ); 
					queryString += ( isFirst ? "" : "&" ) + PARAM_ISNULL + "=" + paramName; 
					isFirst = false;
				}
			}
		}
		if ( getParameter( request, name ) == null )
		{