You might be able to have one interact with the other by keeping them as separate scripts/files, and invoking one from the other via the shell (e.g. PHP's shell_exec()) or via cURL, but they won't co-exist in the same file. Or depending on what you need to do, you might use AJAX on the client side to populate a particular part of the page via a script in the other language.
"Please give us a simple answer, so that we don't have to think, because if we think, we might find answers that don't fit the way we want the world to be."
~ Terry Pratchett in Nation
1. ASP and PHP is 2 different languages and has 2 different compilers, so you can not mix php and asp inside the same page, but you can mix them inside website if your server configured to run php and asp with many restrictions, because it would be different applications even inside the same folder...
2. ASP is Active Server Pages aspx is dot.net. DOT.NET has 2 compilers c# and vb. VB.NET has the same syntax as ASP (vbScript), but more complex, object oriented