input value letter count
HTML
<div>
<textarea id="textBoxId1"></textarea>
<span id="first">500</span>
</div>
<div>
<textarea id="textBoxId2"></textarea>
<span id="second">500</span>
</div>
JavaScript
//count
$('#textBoxId1').bind('keyup', function(e){
$('span#first').text($(this).val().length);
});
//remaining
$('#textBoxId2').bind('keyup', function(e){
$('span#second').text( 500 - $(this).val().length);
});