Javascript Text Counter

HTML EXAMPLE

<table width="100%" border="0" cellspacing="0" cellpadding="0">
 <tr>
  <td class="normal">
	<textarea name="txtBx" cols="30" rows="4" id="txtBx"
		onKeyup="countText('txtBx','countBx',100)" ></textarea>
  </td>
  </tr>
  <tr>
    <td class="normal">
	<input name="countBx" id="countBx" type="text" size="2" 
	maxlength="3" value="100" />characters remaining
	</td>
  </tr>
</table>

JAVASCRIPT CODE


function countText(textArea,displayBx,max_limit){
	
	// get value of form elements
	var element1 = document.getElementById(textArea).value;
	
	// get length of element1
	var len = element1.length;
	
	// set value of remainder
	var remainder = max_limit - len;
	
	// dont allow length of text in element1 to exceed max_limit
	if(len > max_limit){
		
		document.getElementById(textArea).value = element1.substr(0,max_limit);
	}
	// adjust remainder so it doesnt go below zero
	if(remainder < 0){
		remainder = 0;
	}
	
	// set value of displayBx to value of remaider
	document.getElementById(displayBx).value = remainder;
	

}