Question

I have a php script that returns an echo of ‘Hello’ when accessed half the time (just based on a random number).

Is it possible to make a javascript script on a HTML page that will:

Go to the the PHP page,

If ‘Hello’ is returned it will show an alert of ‘Goodbye’

ELSE

It shows ‘nothing found’

What do I need to do this?

Answer 1

That is called AJAX. Example:

var msg = 'Nothing found';
var xhr = new XMLHttpRequest();

xhr.onreadystatechange = function() {
  if (xhr.readyState == 4 && xhr.status == 200) {
    alert(xhr.responseText != "Hello" ? msg : "Goodbye");
  }
};

xhr.open('GET', 'http://example.com', true);
xhr.send(null);

See also:
https://developer.mozilla.org/en/AJAX/Getting_Started