Why am I getting weird results in my Ajax call ? Im so frustrated!!!

[2levelsabove]

The function below has 2 alert boxes. When I run it, sometimes the outer alert box comes empty. Please explain in a human manner why .

 

 

function ItemCount()//returns the number of items in carousel
{


if (window.XMLHttpRequest) {
		var	req = new XMLHttpRequest();
	}
	else if (window.ActiveXObject) {
		var req = new ActiveXObject("Microsoft.XMLHTTP");
	}
	else
	{
	alert("upgrade browser");

	}


	req.open("POST", "/includes/_process/getPortfolioCount.php", true);
	req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	req.send(null);
	req.onreadystatechange = function() {
		if ((req.readyState == 4) && (req.status == 200)) {


			if (req.responseText.length) {


			document.getElementById('portfolioCount').value=req.responseText;

			alert(req.responseText);

			}

		}
	}

alert("out:"+document.getElementById('portfolioCount').value);




return document.getElementById('portfolioCount').value;

}//function 

[Ken2k7]

The purpose of the .readystatechange function is because you don't know when the AJAX information is available. If you put an alert statement outside that function, chances are, the AJAX data hasn't loaded.

[haku]

That's exactly it.

 

On a side note:

 

req.send(null);

 

If you are not actually sending any post data (which you aren't, since you are sending NULL), then it's better to make your AJAX call a 'get' call instead of a 'post' call.