var http_request = false;
var n_refresh = 0;

function makePOSTRequest(url, parameters) {
	http_request = false;
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
	 http_request = new XMLHttpRequest();
	 if (http_request.overrideMimeType) {
		// set type accordingly to anticipated content type
		//http_request.overrideMimeType('text/xml');
		http_request.overrideMimeType('text/html');
	 }
	} 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('Cannot create XMLHTTP instance');
	 return false;
	}
	
	http_request.onreadystatechange = alertContents;
	http_request.open('POST', url, true);
	http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	http_request.setRequestHeader("Content-length", parameters.length);
	http_request.setRequestHeader("Connection", "close");
	http_request.send(parameters);
}

function alertContents() {
	if (http_request.readyState == 4) {
	 if (http_request.status == 200) {
		result = http_request.responseText;
		document.getElementById('div_form_validate_captcha').innerHTML = result;            
	 } else {
		alert('There was a problem with the request.');
	 }
	}
}

function validate_captcha() {
	var poststr = "captcha_input=" + encodeURI( document.getElementById("captcha_input").value );
	makePOSTRequest('captcha_image/validate_captcha.php', poststr);
}

function create_captcha(){
	n_refresh++;
	document.getElementById('captcha_input').value		= ''
	document.getElementById('captcha_im').innerHTML = '<a href="#" onclick="create_captcha();"><img src="captcha_image/utils_captcha/update_captcha.png" border="0" alt="" /></a><img src="captcha_image/captcha_create.php?n_refresh=' + n_refresh + '" border="0" alt="" />';
	return false;
}