<!DOCTYPE html>
<html>
<head>
<title>香港身份證校驗碼計算</title>
</head>
<body>
<input type=text id="no" value="A1234569" />
<div>正確證號為：<label id="result"></label></div>
<button onclick="generate()">計算</button>
<script>
function generate(){
var str = document.getElementById("no").value;
if(str.length!=8){alert("輸入不正確！");return;}
var vNo = generateValidCode(str);
document.getElementById("result").innerHTML = str.substring(0,str.length - 1) + vNo;
}
function generateValidCode(str){
var hash = (str.substring(0,1).toUpperCase().charCodeAt() - 64) * 8;
for(var i = 1;i<=6;i++)
{
hash += parseInt(str.substring(i,i+1)) * (8-i)
}
var validateNo = hash%11;
var ret = "";
if(validateNo==1){
ret = "A";
}else
{
ret = 11 - validateNo;
}
return ret;
}
</script>
</body>
</html>
