function getHTTPObject() { var xmlhttp; 
/*@cc_on @if (@_jscript_version >= 5) try { xmlhttp = new ActiveXObject('Msxml2.XMLHTTP'); } catch (e) { try { xmlhttp = new ActiveXObject('Microsoft.XMLHTTP'); } catch (E) { xmlhttp = false; } } @else xmlhttp = false; @end @*/
if (!xmlhttp && typeof XMLHttpRequest != 'undefined') { try { xmlhttp = new XMLHttpRequest(); } catch (e) { xmlhttp = false; } } return xmlhttp; }

function validEmail( value ) {
    return ( /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(value) );
}


function validateCF( what ){
    if (what.name.value == '' ){
        alert('Please enter your name!');
        return false;
    }
    if (!validEmail(what.email.value) ){
        alert('Please enter your e-mail address correctly!');
        return false;
    }
    if (what.body.value == '' ){
        alert('Please enter your comment!');
        return false;
    }
if ( what.num.value != what.vvnum.value ){
    alert('Please repeat the number exactly!');
    return false;
}
    
    return true;
 }

function getElement(id){
   if (document.all){
       return document.all(id);
   }
   else if (document.getElementById){
       return document.getElementById(id);
   }
}

var requester = getHTTPObject();
var unsubscribe = false;

function processReqChange(){
    if (requester.readyState == 4) {
        if (requester.status == 200) {
		    if ( unsubscribe ){
	            alert('OK, your e-mail address has been removed.');
			} else {
	            alert('OK, subscribed as ' + getElement('email').value + '.');
			}
			getElement('email').value = 'type your e-mail adress here';
        }
    }
}

function newsLetterSignIn( subscribe ){
    unsubscribe = !subscribe;
	
    address = getElement('email').value;
	
	if ( !validEmail( address ) ){
	    alert('Sorry, your e-mail address isn\'t valid.');
		return false;
	}
	
	requester.onreadystatechange = processReqChange;
	if ( unsubscribe ){
	    unsubscribeURI = '&unsubscribe=unsubscribe';
	} else {
	    unsubscribeURI = '';
	}
	requester.open('GET', 'newsletter_signin.php?email=' + escape(address) + unsubscribeURI, true);
	requester.send( null );
	
	return true;
}