Calculating YTD from store procedure

I am trying to calculate YTD (Year to date) salary amount

YTD: "YTD" means Year-To-Date. It is the period starting January 1 of the current year until the last day of the pay cycle. Current means what you made that pay period.

e.g. Your actual pay for January = 15000, for Feb=20000, for march 25000 then YTD of any month will be = to current month pay+ all pays that you got before current month, (only those month in which you got otherwise non paid months will be considered 0)

so my code is to calculate Current month salary via store procedure by passing EmplID and Month manually but i want to calculate YTD which i am unable to so far, HELP please.

USE [a1]
GO
/****** Object:  UserDefinedFunction [dbo].[GetTotalSalary1_func]    Script Date: 2014-02-21 4:12:42 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO


ALTER FUNCTION [dbo].[GetTotalSalary1_func] 
(
	@emplID int,
	@month VARCHAR(50) = NULL
)
RETURNS int
AS
BEGIN
	Declare @StartDate Date,  @EndDate Date, @mydate date, @TotalDays int, @TotalHours int, 
		        @BasicSalary float, @BSalaryHour int, @TotalSalary float, @hms varchar(100),@hrs int, @mts int, @TotalHoursWorked float
set @hms = (Select OverallTime from MonthlyRecord where EmplID = @emplID AND Month = @month )

Set @hrs = LEFT(@hms,charindex(':',@hms)-1)
set @mts=RIGHT(@hms,len(@hms)-charindex(':',@hms))

set @TotalHoursWorked = @hrs + (@mts/60.0)


		
		Set @mydate = GETUTCDATE()
		Set @StartDate = (SELECT CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(@mydate)-1),@mydate),101))
		Set @EndDate = (SELECT CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,@mydate))),DATEADD(mm,1,@mydate)),101))
		Set @TotalDays =((DATEDIFF(dd, @StartDate, @EndDate) + 1)
		  -(DATEDIFF(wk, @StartDate, @EndDate) * 1)
		  -(CASE WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN 1 ELSE 0 END)) 
		Set @TotalHours  = (@TotalDays * 8)
		Set @BasicSalary = (Select BasicSalary from HrEmployee where EmplID=@emplID)
		--Set @TotalHoursWorked = (Select OverallTime from MonthlyRecord where EmplID = @emplID AND Month = @month )
		Set @BSalaryHour = @BasicSalary / @TotalHours
		Set @TotalSalary = @BSalaryHour * @TotalHoursWorked
		--------------------------------------------------------------------------------------
	-- Return the result of the function
	RETURN @TotalSalary

END