sql - condition in where clause with optional parameter -

there thee input parameter in stored procedure. example,

declare @fromdate datetime = null  declare @todate datetime = null declare @id int = null 

i want write condition in clause like...if fromdate provided searching must done on @fromdate. if @fromdate not provided check @id variable if not null search basis on @id...

something like...

     case     when @fromdate not null   (@fromdate null or ([created] between @fromdate , @todate))     else (@requestid null or id=@requestid) 

there 1 problem below solution...if @fromdate , @id both provided intesect of them , nothing return.....condition should like...if @fromdate given priority gives @fromdate if @id provided , result must not dependend @id parameter....

because depend on both parameters can use them both in condition:

where (@fromdate null or ([created] between @fromdate , @todate))  or ((@requestid null or id=@requestid)      , @fromdate null) ----mix @requestid & @fromdate