<script type="text/javascript" language="javascript"> function textCounter(field, maxlimit) { if (document.getElementById(field).value.length > maxlimit) { document.getElementById(field).value = document.getElementById(field).value.substring(0,maxlimit); } else { document.getElementById("remLen").value = maxlimit - document.getElementById(field).value.length; } } </script>
<form runat="server" id="writemsgtxt"><table width="100%" border="0" cellspacing="0" cellpadding="0"> <tr> <td height="22" align="left"> 你還可以留言 <input readonly type="text" id="remLen" runat="server" size="4" maxlength="3" value="500" class="input1" /> 字 </td> </tr> <tr> <td align="left"> <asp:TextBox ID="content" runat="server" CssClass="input2" Rows="8" Columns="50" TextMode="MultiLine" onkeyup="textCounter('content',500)"></asp:TextBox> </td> </tr></table></form>