Question

Javascript

$("#appendedInputButton").click( function () {
    bday = document.getElementById("appendedInputButton").value;
    $.get("php/getWiki.php", {
        "bday":bday
    }, function (data) {
        response = data;
    })
});

Also tried bday w/o the quotes.

PHP

if (isset($_GET["bday"])) {
    var_dump($_GET);
    $bday = $_GET["bday"];
    echo $bday;
    echo "<br>";
    ...
} else {
    echo "error lols."
}

I guess I’m not doing something correctly.
Here is the response outout:

response
"array(1) {
    ["bday"]=>
    string(0) ""
}"

Answer 1

You’re binding the click event to the same input that contains the value, so the first time you click it, there won’t be anything in it to send.

_{(Just posting this as an answer so it’s actually answered ^_^)}