Required Output for Quarter

Hi  ,

I have a table that has customer,product,month ,year and month ,information .Sql Scripts

Create Table SampleRevenue
(Customer varchar(30),
 Product  varchar(30),
 SMonth    int ,
 SYear     int,
 Total Decimal )
 go

 
 Insert into SampleRevenue
 Values('Sam','Switch',1,2014,300.50)
 Insert into SampleRevenue
 Values('Sam','Clutch',1,2014,100)
 Insert into SampleRevenue
 Values('Sam','Viper',1,2014,50)
 Insert into SampleRevenue
 Values('Tom','Viper',1,2014,50)
 Insert into SampleRevenue
 Values('Tom','Viper',2,2014,50)
 Insert into SampleRevenue
 Values('Tom','Belt',2,2014,50)
 Insert into SampleRevenue
 Values('Tom','Dash',3,2014,50)
 Insert into SampleRevenue
 Values('Ron','Dash',3,2014,100)
 Insert into SampleRevenue
 Values('Ron','Dash',4,2014,150)
 Insert into SampleRevenue
 Values('Ron','Dash',4,2014,150)
 Insert into SampleRevenue
 Values('Tom','Dash',4,2014,150)
 Insert into SampleRevenue
 Values('Tom','Belt',5,2014,150)
 Insert into SampleRevenue
 Values('Ron','Viper',5,2014,150)
 Insert into SampleRevenue
 Values('Ron','Belt',5,2014,150)
 Insert into SampleRevenue
 Values('Tom','Belt',5,2014,150)
 Insert into SampleRevenue
 Values('Tom','Belt',5,2014,150)
 Insert into SampleRevenue
 Values('Tom','Belt',6,2014,150)

 go

So like if i want to check the result for the current quarter . The output should be like below :

All the current quarter months, Sum of the Product in the customer column and the difference between the months in the current quarter . Kindly Help