function changeContact() {
	document.daform.submit_button.disabled = true;
	sendEmailAddress(document.daform.email.value);
}

function xmlRequest() {

	http_request = false;

	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		http_request = new XMLHttpRequest();
			if (http_request.overrideMimeType) {
				http_request.overrideMimeType('text/xml');
			}
		} else if (window.ActiveXObject) { // IE
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}

	if (!http_request) {
		alert('Giving up - Cannot create an XMLHTTP instance');
		return false;
	} else {
		return true;	
	}
}

function sendEmailAddress(email) {
	if(xmlRequest()) {
		http_request.onreadystatechange = receiveEmailResponse;
		http_request.open('POST', "/contact/docontact.php", true);
		http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		
		var pInfo = "email=" + email;
		
		http_request.send(pInfo);
	}
}

function receiveEmailResponse() {
	if (http_request.readyState == 4) {
		if (http_request.status == 200) {
			try {
				x = new ActiveXObject("Microsoft.XMLDOM");
				x.async = false;
				x.loadXML(http_request.responseText);
			} catch (e) {
				x = http_request.responseXML;
			}

			s = 'Unknown response from server.';

			var response = x.getElementsByTagName("response");
            if(response.length > 0) s = response.item(0).firstChild.data;

			if(s == "ok") {
				document.getElementById("contactBlock").style.cssText = "display:none";
				document.getElementById("thanksBlock").style.cssText = "display:block";
			}
			else {
				alert('There was a problem with the request.\n'+s);
			}

		} else {
			alert('There was a problem with the request.');
		}
	}
}