Calculate the number of characters in a textarea

Calculate the number of characters in a textarea

<script LANGUAGE="JavaScript">
//onClick event - place in the submit button tag - onclick="return textCounter('element', 'Description', 2000);"

function textCounter(field, fieldname, maxlimit){
var numCharacters = eval('document.frm_daten.'+field+'.value.length');
if (numCharacters > maxlimit) { // if too long
var extraCharacters = numCharacters - maxlimit;
var msg = 'You have entered ' + extraCharacters + ' extra characters in the ' +
fieldname + '. The maximum is ' + maxlimit;
alert(msg);
return false;
}
}
//onChange event place in the textarea tags - onchange="return maxLength('htmlPageTopContainer_frm_daten_inTxtAr_description', 'Description', 2000);"

function maxLength(field, fieldlabel, maxlimit){
var numCharacters = eval('document.frm_daten.'+field+'.value.length');
if (numCharacters > maxlimit) {

var extraCharacters = numCharacters - maxlimit;

var msg = 'You have entered ' + extraCharacters + ' extra characters in the ' +
fieldname + '. The maximum is ' + maxlimit;

alert(msg);
}
}
</script>