Trouble with 'open()' in AJAX

[stuff4web]

Can anyone see whats the problem with this code?

HTML: Select all

<script type="text/javascript">
var xmlHttp;
function stateChanged() { 
 if (xmlHttp.readyState==4) { 
  document.getElementById("mysql_check").innerHTML=xmlHttp.responseText;
 }
}
function getXmlHttpObject() {
 var xmlHttp = null;
 if (window.ActiveXObject) {
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
  } else if (window.XMLHttpRequest) {
    xmlHttp = new XMLHttpRequest();
  }
 return xmlHttp;
}
function mysqlReset() {
 document.getElementById("mysql_check").innerHTML = "<input type=\"button\" value=\"Check Connection\" onClick=\"mysqlCheck()\">"
}
function mysqlCheck() {
 document.getElementById("mysql_check").innerHTML = "Checking...";
 var host = document.getElementById("mysql_host").value;
 var user = document.getElementById("mysql_user").value;
 var pass = document.getElementById("mysql_pass").value;
 var db = document.getElementById("mysql_db").value;
 if (host.length==0 || user.length==0 || pass.length==0 || db.length==0) {
  alert("Please fill in all fields");
  mysqlReset();
  return;
 }
 xmlHttp = getXmlHttpObject;
 if (xmlHttp==null) {
  alert("Your browser doesn't suppert AJAX which is needed to check your connection");
  mysqlReset();
  return;
 }
 var url = "http://www.stuff4web.co.uk/SCMS/admin_check_mysql.php?h="+host+"&u="+user+"&p="+pass+"&d="+db+"&s="+Math.random()*10;
 xmlHttp.onreadystatechange = stateChanged;
 xmlHttp.open("GET",url,true);          // LINE 74
 xmlHttp.send(null);
}
</script>

I am getting the error "Object doesn't support this property or method" on line 74 (marked above)

[Kropotkin]

Hello

On line 41 you have a return statement outside a function. Return is used to return something from a function.

Why not put your what to do if no support for AJAX into the getXmlHttpObject function?

Hope that helps

[Blake121]

I think I have the problem. This should work anyway.

You have :

Code: Select all

xmlHttp.onreadystatechange = stateChanged;
xmlHttp.open("GET",url,true);          // LINE 74

While it should be:

Code: Select all

xmlHttp.open("GET",url,true);          // LINE 73
xmlHttp.onreadystatechange = stateChanged;

You have to open the request before you can tell it what to do with a response.

Blake