JavaScript and function variables

Let us say I have this on a html form...

<input id="world" type="text" onblur="return hello ('world');" />

And in my script I have

function hello (id) {
      document.write(id);
}

It returns world as expected. If I use it like this though...

function hello (id) {
      var val = $('#' + id).val();
      $.post("ajax.php", {
          id: val,
      });
}

Then the id returns Array, how can I make it return username like I want it to.

Thanks.

As requested the php side of things...

if (isset($_REQUEST['username'])) {
    $q = $dbc -> prepare("SELECT username FROM accounts WHERE username = ?");
    $q -> execute(array($_REQUEST['username']));

    if (strlen($_REQUEST['username']) < 3) {
        echo '<div class="error">Has to be at least 3 characters</div>';
    }   
    elseif ($q -> rowCount() > 0) {
        echo '<div class="error">Username already taken</div>';
    }
    else {
         echo '<div class="success">Username available</div>';
    }
}
else {
    echo $_REQUEST;
}

If it should equals username like it should do then the ajax is successfull else it will echo the result of $_REQUEST which is at the moment Array.

UPDATE

Calling the function:

<input id="world" type="text" onblur="return ajax ('username');" />

The original function:

function ajax (id) {

var val = $('#' + id).val();

$('.loading').fadeIn().delay(100);

$.post("ajax.php", {id: val};

}

I did a var dump on the Array and it r开发者_开发知识库eturns the string that was entered into the textfield?? Not the id that I passed to the function?!? Why is this happening?

Example of var_dump($_REQUEST)

array
 'id' => string 'dadadas' (length=7)

---

Your PHP code is checking for username:

if (isset($_REQUEST['username'])) {

Change your code to provide username instead of id

function hello (id) {
    var val = $('#' + id).val();
    $.post("ajax.php", {
        username: val
    });
}

$_REQUEST is an array, which you are echoing because the request parameter username is not being found.

---

You've probably got more than one element on the page with the same "id" value. That's not valid markup, as "id" values must be unique across the entire page.

edit — re-using "id" values is indeed a bad idea, but it wouldn't cause that behavior. I suspect there may be other code involved that would explain more. I'll leave this answer here but nobody should vote for it :-)