Auto-populate month dropdownlist

HTML

<select name="year" id="year"></select>

JavaScript

$(document).ready(function() {
    
    //populate dropdownlist
    var $list = $("#year").append($("<option>"));
    for (var i = 2050; i >= 1900; i--) {
        d.setyear(i); var m = d.toUTCString().substr(8, 3);
        $("<option>", {val: i, text: m}).appendTo($list);        
    }
    
    //onchange event handler
    $(document).on("change", "#year", function() {
        //put your setDay() code here
    });
    
});