Select based on Variable and IF

declare @t int
declare @location varchar (50)
declare @st varchar (50)
declare @sel nvarchar(1000)

set @t =1
set @location='kolkata'
set @st='lela'


if @t=1
begin
set @sel='SELECT count([UserId]) as TotalDonor FROM [vwUser]  where [Location]='''+@location+''''
end

if @t=2
begin
set @sel='SELECT count([UserId]) as TotalDonor FROM [vwUser]  where [Street1]='''+@st+''''

end

   execute sp_executesql @sel