JavaScript CAN Call PHP Functions

So this is where I got to:

function gQ() {
var request = new XMLHttpRequest();
request.open("GET","getQus.php?val=What",false);
request.send();
val = request.responseText;
return val;
}

The thing is, this just gives me a query string, I can get that from PHP directly if I want one, and with less fuss.

Oh well... at least I know it can be done.