jQuery Grid Plugin - jqGrid

I have to check that the record/name is present or not in the generated list means unique name. I have two column in which one is unique so while adding a new entry i need to check that the new name is present or not.

For this i m using the below code but it is not working. can anyne please help me out.

 custom:true,custom_func: function(value,colname){
          var flag = false;
          var allRowsInGrid=$("#editgrid").getGridParam("records");
          for(i=1;i<=allRowsInGrid;i++)
          {
              var rowId = $("#editgrid").getRowData(i);
              var ingredientName = rowId['ingredientName'];
              if(ingredientName == value)
              {
                  flag = true;
              }
         }
         if(flag == true)
              return [false,"Ingredient Name: The Ingredient Name supplied is already in use. Please provide a different Ingredient Name."];
         else
             return [true,""];
      }
      }},