wut wrong with this code?

[nowitzki49]

function checkUsername() {
document.getElementById("username").className = "thinking";
usernameRequest = createRequest();
if (usernameRequest == null)
alert("Unable to create request");
else {
var theName = document.getElementById("username").value;
var username = escape(theName);
var url= "checkName.php?username=" + username;
usernameRequest.onreadystatechange = function showUsernameStatus() {
if (usernameRequest.readyState == 4 || usernameRequest.readyState == "complete") {
var result = usernameRequest.responseText;
alert(result);
if (result == "okay") {
alert("3 okay");
} else {
alert("false");
}
}
}
usernameRequest.open("GET", url, true);
usernameRequest.send(null);
}

in my browser, alert(result) will pop out window okay;
but then pop out another window with false?
}

[Krik]

First try checking the "status" code as well this way the system has to wait till the response from your page has completed.

if ((usernameRequest.readyState == 4 || usernameRequest.readyState == "complete") && usernameRequest.status == 200) {

Then instead of the if/else inside that "if", use a try/catch.

On a side note when posting code use BBcode tags. There is 3 icons above where you type in a question and a response that are for code, HTML, and PHP. They make you code much more readable.

[nowitzki49]

when i change

<?php
    $username = $_REQUEST['username'];
    if(get_user_id_by_username($username) == null){
        echo "okay";
    } else {
        echo "denied";
    }
?>

<?php
    $username = $_REQUEST['username'];
    if(get_user_id_by_username($username) == null){
        echo 1;
    } else {
        echo 0;
    }
?>

and change

function showUsernameStatus() {
  if (usernameRequest.readyState == 4) {
    if (usernameRequest.status == 200) {
      if (usernameRequest.responseText == "okay") {
        document.getElementById("username").className = "approved";
        usernameValid = true;
        checkFormStatus();
      } else if(usernameRequest.responseText == "denied"){
        document.getElementById("username").className = "denied";
        document.getElementById("username").focus();
        document.getElementById("username").select();
        document.getElementById("register").disabled = true;
      }
    }
  }
}

to

function showUsernameStatus() {
  if (usernameRequest.readyState == 4) {
    if (usernameRequest.status == 200) {
      if (usernameRequest.responseText == 1) {
        document.getElementById("username").className = "approved";
        usernameValid = true;
        checkFormStatus();
      } else if(usernameRequest.responseText == 0){
        document.getElementById("username").className = "denied";
        document.getElementById("username").focus();
        document.getElementById("username").select();
        document.getElementById("register").disabled = true;
      }
    }
  }
}

then code work! i think something wrong with the responsetext comparison. Anyone?

[Krik]

You could try an

alert(usernameRequest.responseText);

to see what is being returned and see if there is some variance.

I should also note that you should use FireFox with the FireBug plugin. It is very helpful for diagnosing AJAX issues. Little bit tough to figure out but it can help.