function countChars(theElement, maxCount, textCounter) {
	var realCount, visibleCount, i;
	visibleCount = 0;
	realCount = 0;
	
    if(theElement.value.length > maxCount) {
        theElement.value = theElement.value.substring(0,maxCount);
    }
	
	realCount = theElement.value.length;

	textCounter.innerHTML = maxCount - realCount;
	if (textCounter.value < 0) {
		theElement.value = theElement.value.substring(0, realCount);
		textCounter.innerHTML = 0;
	}
	textCounter.innerHTML += ' caracteres restantes';
}

function getCounter_texto(elm) {
	countChars(elm, 500, document.getElementById('lbl_counter'));
	return;
}