Kontrola poctu znakov v <textarea> za chodu

Kontrola poctu znakov v <textarea> za chodu za pomoci JS, jak urobit aby mi dole ukazovalo kolko mi este ostava znakov do maximalnej velkosti pola? Neviem to vygooglit.

dik souki,

este nieco, nasiel som presne to, co som hladal, vyzera to takto ;)

<SCRIPT LANGUAGE="JavaScript">// function parameters are: field - the string field, count - the field for remaining characters number and max - the maximum number of characters
function CountLeft(field, count, max) {
// if the length of the string in the input field is greater than the max value, trim it
if (field.value.length > max) field.value = field.value.substring(0, max); else
// calculate the remaining characters
count.value = max - field.value.length; } </script>

/////////////////////// HTML ///////////////////////////

<center> <form name=sample action=""> <font size="1" face="arial, helvetica, sans-serif"> Only 50 characters allowed! // at every key up and key down event the upper function is called <input name="text" type="text" size="40" onKeyDown="CountLeft(this.form.text,this.form.left,50);" onKeyUp="CountLeft(this.form.text,this.form.left,50);"> <input readonly type="text" name="left" size=3 maxlength=3 value="50"> characters left</font> </form> </center>