Set value and text of select option from javascript

Question

How can I sett the value and text of a select option from javascript?

function getYear() 
{
    var d = new Date();
    var year = d.getFullYear();
    return year;
}


<select name="dateformat" onchange="change_date();" id="dateformat">
   <option value="??" >??</option>
</select>

I want the value of getYear() in place of ??.

Answer 1

var option = document.getElementById("dateformat").options[0];
option.value = option.text = getYear();

Edit : I thought OP meant to find a way to add an option to a <select> . But it seems it's more like editing an existing one. So there.

Answer 2

There you go:

var year = getYear();
var combo = document.getElementById('dateformat');
combo.options[combo.options.length] = new Option(year ,year );