【Html code】
<table><tr><td>SMS content:</td><td><textarea name="message" cols="96" rows="5" onKeyDown="textCounter(message,remLen,65);"onKeyUp="textCounter(message,remLen,65);"></textarea><td></tr><td><td>You can also enter: <input name="remLen" type="text" value="65" size="5" readonly="readonly"> characters, and the maximum number of characters allowed for each text message is <strong>65</strong> characters</td></tr></table>
【Relevant js code】
<script>function textCounter(field, countfield, maxlimit) {if (field.value.length > maxlimit)field.value = field.value.substring(0, maxlimit);elsecountfield.value = maxlimit - field.value.length;}</script>