code: public String remove(String name)
      {
          String old=null;
          FieldInfo info=getFieldInfo(name);
          Field field=getField(info,true);
  
          if (field!=null)
          {
              old=field._value;
              while(field!=null)
              {
                  field.clear();
                  field=field._next;
              }
          }
          
          return old;
      }
docs: Remove a field.
  @param name