关系管理系统:js代码生成select的出生日期

//page初始调用
function pageInit()
{
    makeYear();
    makeMonth();
    makeDay();
    
}
//产生Year
function makeYear(){
    
    var year = document.getElementById("year");
    
    for(var i=1901;i<=new Date().getYear();i++){
        var option = document.createElement("option");
        option.value = i;
        option.innerText = i;
        year.appendChild(option);
    }
}
//产生Month
function makeMonth()
{
    var month = document.getElementById("month");
    for(var i=2;i<=12;i++)
    {
        var option = document.createElement("option");
        if(i<10)
        {
            option.value = '0' + i;
            option.innerText = '0' + i;
        }else{
            option.value = i;
            option.innerText = i;
        }
        month.appendChild(option);
    }
}
//产生day日
function makeDay()
{
    var day = document.getElementById("day");
    for(var i=2;i<=31;i++)
    {
        var option = document.createElement("option");
        if(i<10)
        {
            option.value = '0' + i;
            option.innerText = '0' + i;
        }else{
            option.value = i;
            option.innerText = i;
        }
        day.appendChild(option);
    }
}

function dosubmit()
{
    makeBirthday();
    makePreference();
    return true;
}
//合成出生日期
function makeBirthday(){
    
    var year = document.getElementById("year").value;
    var month = document.getElementById("month").value;
    var day = document.getElementById("day").value;
    
    var birthday = year + "-" + month + "-" + day;
    
    var input = document.createElement("input");
    input.type="hidden";
    input.name = "birthday";
    input.value = birthday
    
    document.getElementById("customer").appendChild(input);
    
}
//合成爱好单选项
function makePreference()
{
    var preference = "";
    var pres = document.getElementsByName("pre");
    for(var i=0;i<pres.length;i++)
    {
        if(pres[i].checked==true)
        {
            preference = preference + pres[i].value + ",";
        }
    }
    preference = preference.substr(0,preference.length-1);    
    
    var input = document.createElement("input");
    input.type = "hidden";
    input.name = "preference";
    input.value=preference;
    
    document.getElementById("customer").appendChild(input);
    
}