Syntax Errors In SP!

Hi Dears Below is the Sp that i want to use but there are many Syntax erros plz verify and correct them Thnx

create procedure CheckStatus

@EmpID int
as
-- i need some variables so i declared them
declare @ShiftId int
declare @DayTime smalldatetime
declare @ShiftStartT smalldatetime
declare @ShiftEndT smalldatetime
declare @ShiftInOutStatus int
declare @ShiftValidity bit
declare @RTValue int


-- Now i m assigning the values to the declared variable by selecting some value from tables
-- from this point i m having syntax erroes i dont know what are they all atables and all fields are ok verified

set @ShiftId=SELECT S_Id FROM Emp_Info WHERE Emp_Info.Emp_Id=@EmpID
set @DayTime=SELECT GETDATE()
set @ShiftStartT=SELECT S_ST FROM Emp_Shift WHERE Emp_Shift.S_Id=@ShiftId
set @ShiftEndT=SELECT S_ET FROM Emp_Shift WHERE Emp_Shift.S_Id=@ShiftId
set @InOutStatus=SELECT IOStatus FROM Emp_Status WHERE Emp_Status.Emp_Id=@EmpId
-- here i m using a nested case for some checks to insert values into tables
CASE -- Main Case
WHEN @InOutStatus=0 OR @InOutStatus=-1
-- Calling udf_IsShiftValid(datetime,datetime,datetime) a function that ia also ok and returns two possible value 0 or 1
THEN @ShiftValidty=udf_IsShiftValid(@ShiftStartT,@ShiftEndT,@DayTime)
CASE --nested case starts here
WHEN @ShiftValidity=1-- Insertin value into Emp_Status table and assihning value to @RTValue
THEN (INSERT INTO Emp_Status(IOStatus) VALUES(@ShiftValidity) WHERE Emp_Status.Emp_Id=@EmpID
SET @RTValue=1)
WHEN @ShiftValidity=0 THEN SET @RTValue=-1
END-- Nested case End Here
WHEN @InOutStatus=1
THEN
INSERT INTO Emp_Status(IOStatus) VALUES(0) WHERE Emp_Status.Emp_Id=@EmpID
SET @RTValue=0
END

RETURN @RTValue

GO