window.onload = function() {
	initialize();
}

function initialize() {
	initMaxLength();
}

function initMaxLength() {
	var x = document.getElementsByTagName('textarea')[0];
	if(x && x.getAttribute('maxlength'))
	{
		var counter = document.getElementById('counter');
		counter.innerHTML = '0/' + x.getAttribute('maxlength');
		x.relatedElement = counter;
		x.onkeyup = x.onchange = checkMaxLength;
		x.onkeyup();
	}
}

function checkMaxLength() {
	var maxLength = this.getAttribute('maxlength');
	var currentLength = this.value.length;
	if (currentLength > maxLength)
		this.relatedElement.className = 'error';
	else
		this.relatedElement.className = '';	
	this.relatedElement.firstChild.nodeValue = '' + currentLength + '/' + maxLength;
}