```
<html> 
<head> 
<title>Ajax</title> 
<script type="text/JavaScript" src="jquery-1.5.1.min.js"></script> 
<script type="text/JavaScript"> 

function register()
{ 
    $.ajax({
    type: "GET",
    url: "http://exampleurl.com/api/index.php",
    data: "action=login_user&app_key=MyAPIKey&username=Bob&password=HisPassword",
    dataType: "text",
    success: function(data) 
         {
                    alert(data);
         }
    error: function (jqXHR, textStatus, errorThrown) 
         {
                    alert(errorThrown);
         }
          });
}
</script> 

</head> 
<body> 
<form>      
<input type="button" value="Test" onclick="register()"/>
</form>
</body> 
</html>

```

The URL returns a string (plain-text) when used in the address bar. Why is the above code not working? When I click on the button, I get no alert. Basically, nothing happens. 

Browsers tried: IE 8 and Chrome. 

Thank you for your time.