anchor.diff:          
           leftOp = request.getParameter("leftOp");
           rightOp = request.getParameter("rightOp");
  -        if(rightOp == null) rightOp = "";
  -        if(leftOp == null) leftOp = "";
  +
  +        if (rightOp == null) {
  +            rightOp = "";
  +        } else {
  +            rightOp = Encode.forHtml(rightOp);
  +        }
  +
  +        if (leftOp == null) {
  +            leftOp = "";
  +        } else {
  +            leftOp = Encode.forHtml(leftOp);
  +        }
       }
   %>
   
  
positive.code:         }
          if (rightPropertyValue == null) {
              rightPropertyValue = "";
          }
          
          authorNameNegate = request.getParameter("authorNameNegate"); 
  
negative.code:         if (mediaType == null) {
              mediaType = "";
          } else {
              mediaType = Encode.forHtml(mediaType);
              hasParameters = true;
          }
          
  