Change your syntax to this:
DECLARE @previousstatus nvarchar(50)
DECLARE @presentstatus nvarchar(50)
Select @previousstatus = statu FROM ssse where ID = (Select max(id) From ssse)
IF Enddateparameter < cast(getdate() as date)
Begin
Set @presentstatus = 'Inactive'
End
IF @previousstatus = 'Inactive'
BEGIN
Insert INTO ssse(startdate,enddate,status) VALUES(startdateparameter,enddateparameter,@presentstatus)
END