var xmlHttp;

function GetXmlHttpObject() {
	try	{
		// Firefox, Opera 8.0+, Safari
		xmlHttp = new XMLHttpRequest();
	}
	catch(e) {
		// Internet Explorer
		try	{
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch(e) {
			try {
				xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch(e) {
				alert("Your browser does not support AJAX!");
				return false;
			}
		}
	}
}

function calculateRate(fromCurrId, toCurrId, amount) {
	GetXmlHttpObject();
	url = "convertrateajax.php";
	url = url + "?fromCurrId=" + fromCurrId + "&toCurrId=" + toCurrId + "&amount=" + amount;
	xmlHttp.onreadystatechange = stateChanged;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
}

function stateChanged() {
	if(xmlHttp.readyState == 4 || xmlHttp.readyState == "complete") {

		strResponseText = xmlHttp.responseText;

		document.getElementById("spnAmount").innerHTML = strResponseText;
	}
}