function getXMLHttpRequest() {
	var xhr = null;
	
	if (window.XMLHttpRequest || window.ActiveXObject) {
		if (window.ActiveXObject) {
			try {
				xhr = new ActiveXObject("Msxml2.XMLHTTP");
			} catch(e) {
				xhr = new ActiveXObject("Microsoft.XMLHTTP");
			}
		} else {
			xhr = new XMLHttpRequest(); 
		}
	} else {
		alert("Votre navigateur ne supporte pas l'objet XMLHTTPRequest...");
		return null;
	}
	
	return xhr;
}

function is_code_valid(){
	
	var xhr = new getXMLHttpRequest();
	
	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4 && (xhr.status == 200 || xhr.status == 0)) {	
			
			var codev_user = document.getElementById("codev_input_text").value;
			codev_user = codev_user.toUpperCase();
			text_user = xhr.responseText;
			text_user = text_user.toUpperCase();
			
			if((codev_user == text_user) && (codev_user != '') ){
				document.getElementById("codev_validation_message").innerHTML = "Validation OK.";
				document.getElementById("codev_validation_message").style.color = "#2fc41c";
				document.getElementById("codev_validation_finale").style.display = "block";
				document.getElementById("codev_validation_finale").innerHTML = '<input type="submit" value="Envoyer" name="envoyer">&nbsp;&nbsp;&nbsp;<input type="reset" value="Corriger" name="Corriger">';
			}else{
				document.getElementById("codev_validation_message").innerHTML = "Recopiez le code, le bouton 'Envoyer' apparaitra ensuite.";
				document.getElementById("codev_validation_message").style.color = "#FF0000";
				document.getElementById("codev_validation_finale").style.display = "none";
				document.getElementById("codev_validation_finale").innerHTML = '';
			}
			
		} else if (xhr.readyState < 4) {
			
		}
	};
	
	xhr.open("GET", "captcha/XMLHttpRequest.php?" + "ask_codev" + "=" + "1", true);
	xhr.send(null);
	
}