年龄验证
<script type="text/javascript">function checkAge(){var age=form1.age.value;if (isNaN(age)) {alert('请输入正确的数字');return false;}if(age<=0 || age>=200){alert("您输入的年龄有误");}else{if(age>80){alert("老年人");}else if(age>60){alert("中老年人");}else if(age>40){alert("中年人");}else if(age>20){alert("青年人");}else{alert("青少年");}}}</script>?