i try any thing you sayed but i cant do my job its my code
Func<Dead, Object> orderByFunc = null;
orderByFunc = Dead => Dead.Last_Name;
var query = from ded in searchDead
join ask in Asker on ded.Family_Number equals ask.Family_Number
orderby orderByFunc
select ask;
Functions.searchAsker = query.AsQueryable<Asker>();