CREATE PROCEDURE dbo.wec_GetWeight(@weight_kg varchar(20) output, @CurrWeight numeric(8,4), @Weight_Unit varchar(5))
AS
BEGIN

  if @Weight_Unit = 'g'
    Set @weight_kg = @CurrWeight / 1000

  else	if @Weight_Unit = 'kg'
    Set @weight_kg = @CurrWeight

  else if  @Weight_Unit = 't'
    Set @weight_kg = @CurrWeight*1000

Set @weight_kg = Cast (@weight_kg as numeric(8,4))

END
GO