JS 提示输入字符数
<script type="text/javascript">function checkLength(which) {var maxChars = 250;if (which.value.length > maxChars)which.value = which.value.substring(0,maxChars);var curr = maxChars - which.value.length;document.getElementById("chLeft").innerHTML = curr.toString();}</script><table> <tr> <td> <textarea name="description" onkeyup="checkLength(this);"></textarea><br /><small><font color="red">文字最大长度: 100. 还剩:</font><font color="blue"> <span id="chLeft">100</span>.</font></small> </td> </tr> </table>