function GetXmlHttpObject() {
	var xmlHttp = null;
	try {
		// Firefox, Opera 8.0+, Safari
		xmlHttp = new XMLHttpRequest();
	}
	catch (e) {
		//Internet Explorer
		try {
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e) {
			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	return xmlHttp;
}

function getStock(scActionZero) {
	var stylecode = document.getElementById('w63_sl').value;
	var colour = document.getElementById('ddm_colour')[document.getElementById('ddm_colour').selectedIndex].innerHTML;
	var pid = document.getElementById('w63_pid').value;

	var http = GetXmlHttpObject();

	var url = 'stock_lookup.php?sc=' + stylecode + '&scaz=' + scActionZero + '&c=' + colour + '&pid=' + pid + '&cs=';

	var radios = document.getElementsByName('size');
	var radios_len = radios.length;
	for (ri = 0; ri < radios_len; ri++) {
		radio_value = radios[ri].value;
		radio_split = radios[ri].id.split('_');
		radio_size = radio_split[1];

		url += radio_size + '|' + radio_value;

		if (ri < radios_len - 1) {
			url += ',';
		}
	}

	http.open('GET', url, true);
	http.onreadystatechange = function() {
		if (http.readyState == 4 || http.readyState == 'complete') {
			document.getElementById('sizes_div').innerHTML = http.responseText;
		}
		else {
			document.getElementById('sizes_div').innerHTML = '<p><img src="images/ajax-loader.gif" width="16" hieght="16" alt="Checking stock levels"/> Checking stock...</p>';
		}
	}
	http.send(null);
}