Why can't I write JavaScriptAJAX like this? It's strange!

In this case, the server will not receive the code {code...}, but the server will receive the code. Why? If the code {code...} is written like this, the server cannot receive:

Xmlhttp. open ("POST", "03.php", true); // cannot receive!

But the server will receive the message. Why?

Var url = "03.php"; // This is a strange way! Xmlhttp. open ("POST", url, true );

Reply content:

In this case, the server cannot receive:

Xmlhttp. open ("POST", "03.php", true); // cannot receive!

But the server will receive the message. Why?

Var url = "03.php"; // This is a strange way! Xmlhttp. open ("POST", url, true );

I can't see any errors with this code.

The two js methods are basically the same.