MySQL Query + ASP IF Else End IF

example :

Sql = "Select * From tablo Where Baslik = "&strBaslik&" And Ozellik IN ("&strOzellik&") Order By Id Desc"

i want :

Sql = "Select * From tablo Where Baslik = "&strBaslik&" IF Not "&strOzellik&" = Then And Ozellik IN ("&strOzellik&") End IF Order By Id Desc"

like this

How do I do this?

Thanks.