public String weekAdd(String field)
    {
         String newField = " ADD ";
         String number = "";

         for(int i = 1; i <= field.length(); i++)
         {
            if(isNumber(field.substring(i - 1, i)))
            {
                number = number + field.substring(i - 1, i);
            }
            else
            {
                number = "~invalid~";
                break;
            }
            boolean over = false;

                 try
                 {
                     if(Integer.parseInt(number) > 7)
                     {
                         over = true;
                     }

                 }catch(Exception e)
                 {
                     System.out.println("not a integer");
                 }

                if(over)
                {
                    number = "~invalid over~";
                    break;
                }

        }
          boolean under = false;
                 try
                 {
                     if(Integer.parseInt(number) < 1)
                     {
                        under = true;
                     }

                 }catch(Exception e)
                 {
                     System.out.println("not a integer");
                 }

                if(under)
                {
                    number = "~invalid under~";
                }
         newField = newField + number;
         return newField;
     }