// JavaScript Document

// form validation function //
function validate(form) {
	var name = form.author.value;
	var email = form.email.value;
	var message = form.comment.value;
	
	var nameRegex = /^[a-zA-Z]+(([\'\,\.\- ][a-zA-Z ])?[a-zA-Z]*)*$/;
	var emailRegex = /^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$/;
	var messageRegex = new RegExp(/<\/?\w+((\s+\w+(\s*=\s*(?:".*?"|'.*?'|[^'">\s]+))?)+\s*|\s*)\/?>/gim);
	
	if((name == "Nome (richiesto)")||(name == "")) {
		inlineMsg('author','Devi inserire il nome',2);
		return false;
	}
	if(!name.match(nameRegex)) {
		inlineMsg('author','Devi inserire un nome valido',2);
		return false;
	}
	if((email == "Email (richiesta)")||(email == "")) {
		inlineMsg('email','<strong>Error</strong><br />Devi inserire il tuo indirizzo Mail',2);
		return false;
	}
	if(!email.match(emailRegex)) {
		inlineMsg('email','<strong>Error</strong><br />Hai inserito una Mail invalida',2);
		return false;
	}
	if(message == "") {
		inlineMsg('comment','Devi inserire il messaggio');
		return false;
	}
	if(message.match(messageRegex)) {
		inlineMsg('comment','Hai inserito una messaggio invalido');
		return false;
	}
	return true;
}

// START OF MESSAGE SCRIPT //

var MSGTIMER = 20;
var MSGSPEED = 5;
var MSGOFFSET = 3;
var MSGHIDE = 3;

// build out the divs, set attributes and call the fade function //
function inlineMsg(target,string,autohide) {
	var msg;
	var msgcontent;

	if(!document.getElementById('msg')) {
		msg = document.createElement('div');
		msg.id = 'msg';
		msgcontent = document.createElement('div');
		msgcontent.id = 'msgcontent';
		document.body.appendChild(msg);	
		msg.appendChild(msgcontent);
		msg.style.filter = 'alpha(opacity=0)';
		msg.style.opacity = 0;
		msg.alpha = 0;
	} else {
		msg = document.getElementById('msg');
		msgcontent = document.getElementById('msgcontent');
	}
	msgcontent.innerHTML = string;
	msg.style.display = 'block';
	var msgheight = msg.offsetHeight;
	var targetdiv = document.getElementById(target);
	targetdiv.focus();
	var targetheight = targetdiv.offsetHeight;
	var targetwidth = targetdiv.offsetWidth;
	var topposition = topPosition(targetdiv) - ((msgheight - targetheight) / 2);
	var leftposition = leftPosition(targetdiv) + targetwidth + MSGOFFSET;
	msg.style.top = topposition + 'px';
	msg.style.left = leftposition + 'px';
	clearInterval(msg.timer);
	msg.timer = setInterval("fadeMsg(1)", MSGTIMER);
	if(!autohide) {
		autohide = MSGHIDE;
	}
	window.setTimeout("hideMsg()", (autohide * 1000));
}

// hide the form alert //
function hideMsg(msg) {
	var msg = document.getElementById('msg');
	if(!msg.timer) {
		msg.timer = setInterval("fadeMsg(0)", MSGTIMER);
	}
}

// face the message box //
function fadeMsg(flag) {
  if(flag == null) {
    flag = 1;
  }
  var msg = document.getElementById('msg');
  var value;
  if(flag == 1) {
    value = msg.alpha + MSGSPEED;
  } else {
    value = msg.alpha - MSGSPEED;
  }
  msg.alpha = value;
  msg.style.opacity = (value / 100);
  msg.style.filter = 'alpha(opacity=' + value + ')';
  if(value >= 99) {
    clearInterval(msg.timer);
    msg.timer = null;
  } else if(value <= 1) {
    msg.style.display = "none";
    clearInterval(msg.timer);
  }
}

// calculate the position of the element in relation to the left of the browser //
function leftPosition(target) {
  var left = 0;
  if(target.offsetParent) {
    while(1) {
      left += target.offsetLeft;
      if(!target.offsetParent) {
        break;
      }
      target = target.offsetParent;
    }
  } else if(target.x) {
    left += target.x;
  }
  return left;
}

// calculate the position of the element in relation to the top of the browser window //
function topPosition(target) {
  var top = 0;
  if(target.offsetParent) {
    while(1) {
      top += target.offsetTop;
      if(!target.offsetParent) {
        break;
      }
      target = target.offsetParent;
    }
  } else if(target.y) {
    top += target.y;
  }
  return top;
}

// preload the arrow //
if(document.images) {
  arrow = new Image(7,80);
  arrow.src = "msg_arrow.gif";
}