SO - 17107061

HTML

<button>Add Options</button>
<br/>
<select id="ddlAgentName"></select>
<br />

JavaScript

$('button').click(function () {
    var myOptions = {
        val1: 100,
        val2: 'text2'
    };
    var $mySelect = $('#ddlAgentName');
    $.each(myOptions, function (val, text) {
        $mySelect.append($('<option />', {
            value: val,
            text: text
        }));
    });
});