我正在尝试 Build 一个网页,其表格要求soemone填写一年的下拉菜单,但我也希望它根据年份改变,即:它现在是2014年所以我想要显示2014年,2015年,2016年,2017年,2018年 . 2015年将显示2015年,2016年,2017年,2018年,2019年 .
我有以下用于表单的html代码
<td valign="top">
<select name="month" id="month">
<option value="1">January</option>
<option value="2">February</option>
<option value="3">March</option>
<option value="4">April</option>
<option value="5">May</option>
<option value="6">June</option>
<option value="7">July</option>
<option value="8">August</option>
<option value="9">September</option>
<option value="10">October</option>
<option value="11">November</option>
<option value="12">December</option>
</select>
<select name="day" id="day">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<option value="11">11</option>
<option value="12">12</option>
<option value="13">13</option>
<option value="14">14</option>
<option value="15">15</option>
<option value="16">16</option>
<option value="17">17</option>
<option value="18">18</option>
<option value="19">19</option>
<option value="20">20</option>
<option value="21">21</option>
<option value="22">22</option>
<option value="23">23</option>
<option value="24">24</option>
<option value="25">25</option>
<option value="26">26</option>
<option value="27">27</option>
<option value="28">28</option>
<option value="29">29</option>
<option value="30">30</option>
<option value="31">31</option>
</select>
<select name="year" id="year">
<option value="2014">2014</option>
<option value="2015">2015</option>
<option value="2016">2016</option>
<option value="2017">2017</option>
<option value="2018">2018</option>
</select>
<label>
<input type="radio" name="Date" value="firm" id="Date0" />
firm</label>
<label>
<input type="radio" name="Date" value="flexible" id="Date1" />
flexible</label>
</td>`
我正在考虑使用javascript来更新它
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<script type="text/javascript">
var selOptions = [
['2014','2014','2015','2016','2017','2018'],
['2015','2015','2016','2017','2018','2019'],
['2016','2016','2017','2018','2019','2020'],
['2017','2017','2018','2019','2020','2021'],
['2018','2018','2019','2020','2021','2022'],
['2019','2019','2020','2021','2022','2023'],
['2020','2020','2021','2022','2023','2024'],
['2021','2021','2022','2023','2024','2025']
];
function setSel2Options(obj){
oSel2.options.length = 0;
if(obj.selectedIndex == 0){return;}
for(i=0; i < selOptions.length; i++){
if(obj.value == selOptions[i][0]){
oSel2.options[oSel2.options.length] = new Option('Select a year','',false,false);
for(j=1; j < selOptions[i].length; j++){
oSel2.options[oSel2.options.length] = new Option(selOptions[i][j],selOptions[i][j],false,false);
}
i = selOptions.length;
}
}
}
window.onload=function(){
oSel1 = document.getElementById('sel1');
oSel2 = document.getElementById('sel2');
oSel1.options[oSel1.options.length] = new Option('Select an option','',false,false);
for(i=0; i < selOptions.length; i++){
oSel1.options[oSel1.options.length] = new Option(selOptions[i][0],selOptions[i][0], false,false);
}
oSel1.onchange=function(){setSel2Options(this);}
}
</script>
</head>
<body>
<select id="sel1"></select>
<select id="sel2"></select>
</body>
</html>
这有可能吗?