不知道为什么代码运行不了？说是正则表达式错误
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<style>
input[type=text]{width:40px;border-color: #bbb;height: 25px;font-size: 14px;border-radius: 2px;outline: 0;border: #ccc 1px solid;padding: 0 10px;-webkit-transition: box-shadow .5s;margin-bottom: 15px;}
input[type=text]:hover,input[type=text]:focus,input[type=submit]:hover{border: 1px solid #56b4ef; box-shadow:inset 0 1px 3px rgba(0,0,0,.05),0 0 8px rgba(82,168,236,.6); -webkit-transition: box-shadow .5s;}
input::-webkit-input-placeholder {color: #999; -webkit-transition: color .5s;}
input:focus::-webkit-input-placeholder, input:hover::-webkit-input-placeholder {color: #c2c2c2; -webkit-transition: color .5s;}
input[type=submit]{height: 30px; width: 80px; background:#4393C9; border:1px solid #fff;color: #fff;font:14px bolder;}
#result{background: #56b4ef;width: 300px;height: 50px;}
</style>
<title>正则表达式</title>
</head>
<body>
<form id="form">
年份<input type="text" name="year">
月份<input type="text" name="month">
<input type="submit" value="查询">
</form>
<div id="result"></div>
<script>
function checkYear(obj){
if(!obj.value.match(/^0/)){
obj.style.borderColor = 'red';
result.innerHTML = '输入错误,年份为4位数字表示';
return false;
}
result.innerHTML = '';
return true;
}
function checkMonth(obj){
if(!obj.value.match(/^((0?[1-9])|(1[012]))$/)){
obj.style.borderColor = 'red';
result.innerHTML = '输入错误，月份为1~12之间';
return false;
}
result.innerHTML = '';
return true;
}
var form = document.getElementById('form');
var result = document.getElementById('result');
var input = document.getElementsByTagName('input');
form.onsubmit = function(){
return checkYear(inputs.year) && checkMonth(inputs.month);
};
inputs.year.onfocus = function(){
this.style.borderColor = '';
};
inputs.month.onfocus = function(){
this.style.borderColor = '';
};
if(!String.prototype.trim){
String.prototype.trim = function(){
return this.replace(/^[\s\uFEFF\xA0]+|[\s\uFEFF]\xA0$+/);
};
}
input.year.onblur = function(){
this.value = this.value.trim();
checkYear(this);
};
input.month.onblur = function(){
this.value = this.value.trim();
checkMonth(this);
};
</script>
</body>
</html>
应该是下图所示
