Try this.

create function dbo.[F_GetPreviousDayAndAmount] (@ID char(5),@InjectedDate datetime)

RETURNS [float]

as

BEGIN

declare @YesterdayAmount float ,@PrevDate datetime

select@PrevDate = max(InjectedDate)

from[dbo].[Transactions]

where[ID] = @ID and

[InjectedDate] < @InjectedDate

if @PrevDate is NULL

select@YesterdayAmount = NULL

else

begin

select@YesterdayAmount = [Amount]

from[dbo].[Transactions]

where[ID] = @ID and

[InjectedDate] = @PrevDate

end

RETURN @YesterdayAmount

END

GO

selecta.ID,a.[InjectedDate],a.[Amount],dbo.[F_GetPreviousDayAndAmount](ID,InjectedDate) 'Yesterday_Amount'

from[dbo].[Transactions] a

order by a.ID,a.InjectedDate