如何判断年龄大于18岁
1.jquery的实现方式：
下面这个：
(1)var birth = document.getElementById("dateBirth").children[1].value;
???? 它是用来获取struts2.0的日期控件，输入日期然后获取输入值的方式。
(2)var agree = document.signupFormSubmit.ch1Agree.checked;
??? 它是用来获取chekbox复选框，是否被选中。如果选中则为true,否则是false。
<script type='text/javascript'>$(function(){$("#signupFormSubmit").submit(function(){var agree = document.signupFormSubmit.ch1Agree.checked;var birth = document.getElementById("dateBirth").children[1].value;var myDate = new Date();var str = birth.split("/");if(myDate.getFullYear() - str[2] > 18){if(agree == false){alert("You have to read and agree terms of use to sign up");return false;}}else if(myDate.getFullYear() - str[2] == 18){if(myDate.getMonth()+1 - str[0] > 0){if(agree == false){alert("You have to read and agree terms of use to sign up");return false;}}else if(myDate.getMonth()+1 - str[0] == 0){if(myDate.getDate() - str[1] >= 0){if(agree == false){alert("You have to read and agree terms of use to sign up");return false;}}else{alert("your age less then 18");return false;}}else{alert("your age less then 18");return false;}}else{alert("your age less then 18");return false;}});})</script>?
2.javascript的判断方式：
function checkDateBirth(){var agree = document.signupFormSubmit.ch1Agree.checked;var birth = document.getElementById("dateBirth").children[1].value;var myDate = new Date();var str = birth.split("/");if(myDate.getFullYear() - str[2] > 18){alert(">18");if(agree == true){alert(">18 ==true tijiao");document.getElementById("signupFormSubmit").submit(); return true;}else{alert(">18 ==false ?");alert("you should agree with the terms");return false;}}else if(myDate.getFullYear() - str[2] == 18){alert("==18");if(myDate.getMonth()+1 - str[0] > 0){alert(">3");if(agree == true){alert(">3 ==true tijiao");document.getElementById("signupFormSubmit").submit(); return true;}else{alert(">3 ==false ?");alert("you should agree with the terms");return false;}}else if(myDate.getMonth()+1 - str[0] == 0){alert("==3");if(myDate.getDate() - str[1] >= 0){alert(">=14");if(agree == true){alert(">=14 ==true tijiao");document.getElementById("signupFormSubmit").submit(); return true;}else{alert(">=14 ==false");alert("you should agree with the terms");return false;}}else{alert("<14");alert("your age less then 18");return false;}}else{alert("<3");alert("your age less then 18");return false;}}else{alert("<18");alert("your age less then 18");return false;}}?