insert, update store procedure in sqlserver

Question

i'am facing a problem to update stored procedure :

 

both are working right insert and update procedure but facing a problem when  first time insert product but when update my quantity then it update but i want when any item add in cart then it no add that product :

 

 

@SessionId varchar(500),

@Product_Fkid int,

@size_Fkid int,

@Qty int

AS

Declare @count int,@ReturnValue int

BEGIN

Set @count=(Select COUNT(1) from dbo.MyCart where SessionId=@SessionId and Product_Fkid=@Product_Fkid)

if(@count=0)

begin

Insert into dbo.MyCart(SessionId,Product_Fkid,Qty,size_Fkid) values (@SessionId,@Product_Fkid,@Qty,@size_Fkid)

Set @ReturnValue=1

end

set @count =(select COUNT(1) from dbo.MyCart where Product_Fkid=@Product_Fkid and SessionId=@SessionId and Qty!=0 )

if(@count =1)

begin

set @ReturnValue =3

end

else

begin

update dbo.MyCart

Set Qty=@Qty

where SessionId=@SessionId and Product_Fkid=@Product_Fkid

Set @ReturnValue=2

end

return @ReturnValue