function postEmail()
{
    if (emailIsValid()) {
	$.ajax({
	    type: "POST",
	    url: "email.php",
	    data: "email=" + document.forms["emailform"]["emailaddress"].value,
	    success: function(msg){
		if (msg != 'Thank you. \n')
		    $("#emailError").text(msg);
		else {
		    $("#email").text(msg);
		    $("#emailform").hide();
		}
	    }
	});
    }

    return false;
}

function emailIsValid()
{
    var x=document.forms["emailform"]["emailaddress"].value
    var atpos=x.indexOf("@");
    var dotpos=x.lastIndexOf(".");
    if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length) {
	$("#emailError").text("Please enter a valid email address.");
	return false;
    }
    
    return true;
}