如果复选框被选中，后面的文本框属性为必填

 if($("#taskDepartment_1").prop("checked")){ 2 $('#taskImplement_1').validatebox({ required: true }); 3 } 

<tr>
                                    <th id="task1" >救助保护</th>
                                    <td ><input id = 'taskDepartment_1'
                                        name='taskDepartment_1' type="checkbox" value="1"
                                        <c:if test="${task.taskDepartment_1.contains('1')}">checked="checked"</c:if> disabled="disabled">民政部门</input>
                                    </td>
                                    <td><textarea 
                                        id="taskDescribe_1" name="taskDescribe_1"
                                        class="easyui-validatebox inputdf90" style="height: 80px;"
                                        data-options="required: false, validType: 'length[0,500]'"
                                        maxlength="500" readonly="readonly">${task.taskDescribe_1}</textarea></td>
                                    <td><textarea
                                            id="taskImplement_1" name="taskImplement_1"
                                            class="easyui-validatebox inputdf90" style="height: 80px;"
                                            data-options="required: false, validType: 'length[0,500]'"
                                            maxlength="500">${task.taskImplement_1}</textarea></td>
 </tr>