How custom exception

      #region how custom exception 
            Console.WriteLine ( " Please enter the computer prices (an integer) -----> " );
             the try 
            { 
                int inputPCNum = Convert.ToInt32 (Console.ReadLine ()); 
                PcPrice P = new new PcPrice () ; 
                P.SET (inputPCNum); 
                Console.WriteLine ( " transaction, the customer is very satisfied with the price " ); 
            } 
            the catch (Exception EX) 
            { 
                // output abnormality information 
                Console.WriteLine ( " ---------- ----- ---------------- processing anomaly " );
                Console.WriteLine ( " exception information: {0} " , ex.Message); 
                Console.WriteLine (ex.Data [ " Time " ]); 
                Console.WriteLine ( " For more information Help exception: {0} " , EX .HelpLink); 
                Console.WriteLine ( " --------------- abnormality in the end portion ----------------------- " ); 
            } 
            the finally { 
                Console.WriteLine ( " up code is executed " ); 
            } 
            #endregion 

     public  class PcPrice 
    { 
        Internal  voidSET ( int n-) 
        {                                     
            // check whether it is greater than 5000 
            IF (n-> 5000 ) 
            { 
                // create a custom object class exception e 
                HiPriceException e = new new HiPriceException ( " Computer pricing than 5000, customer dissatisfaction adjust price " ) ;
                 // add the current time to the target e Data property 
                e.Data.Add ( " time " , String .Format ( " time of the exception: {0} " , the DateTime.Now));
                 // the help information e Url assigned to object attribute HelpLink 
                e.HelpLink =" Www.baidu.com " ;
                 the throw e; 
            } 
            // check whether it is greater than 3000 
            the else  IF (n-< 3000 ) 
            { 
                // create a custom object class exception e 
                HiPriceException e = new new HiPriceException ( " Computer pricing than 3000, the customer adjust satisfied price " );
                 // add the current time to the Data property e object 
                e.Data.Add ( " time " , String .Format ( " time of the exception: {0} " , the DateTime.Now)) ;
                 //HelpLink property Url help information assigned to the object e 
                e.HelpLink = " www.baidu.com " ;
                 the throw e; 
            } 
            Console.WriteLine ( " this computer pricing 0} { " , n-); 
        } 
    } 

    // /  <Summary> 
    /// custom exception class HiPriceException, and inherits ApplicationException
     ///  </ Summary> 
    class HiPriceException: ApplicationException 
    { 
        // default constructor 
        Internal HiPriceException () {} 

        // overloaded constructor, inherits method 
        Internal HiPriceException ( String m):base(m) { }

    }