Countdown characters in textbox to label not working

[hackerby]

In this scernario, I have a textbox and a label of which the label is a countdown of the remaining characters available in the textbox. E.g. "239 characters remaining".I personally want to use the javascript function a couple of times, so I want to pass to the variables to the function. These being, maxlength (for length), textbox (for the field) and label (for the counter label).However, the issue I have is that this is simply not working. Just to make sure it wasn't just an IE thing, I tested it in Firefox 18 and it's also producing the same where where label does not change... It's almost like the onKeyUp method is note being called.Anyways my code.JavaScript\[code\]<script type="text/javascript"> function countCharacters(textbox, label, maxcount) { var count = parseInt(document.getElementById(textbox).value.length); document.getElementById(label).innerHTML = maxcount - count; }\[/code\]Label and Textbox\[code\] <asp:TextBox ID="tbComment01" runat="server" CssClass="txt" TextMode="MultiLine" Width="500px" Visible="false" MaxLength="500"></asp:TextBox> <br /> <asp:Label ID="lbCommentCount01" runat="server" Text="Label" Visible="false" CssClass="size11_text_blurb"></asp:Label>\[/code\]Code Behind\[code\]tbComment01.Attributes.Add("onKeyUp", "countCharacters(" + tbComment01.ClientID + "," + lbCommentCount01.ClientID + ", 500)");\[/code\]Cheers all! Trent