Select option list access with Javascript

function populateselection(input) { 
for (i=0;i < input.options.length; i++) 
{ input.options[i].selected ? chosenoption=input.options[i].value : donothing=donothing }

window.status=chosenoption 

}

<form name="selectinterface">
<select name="refererselect" onchange="populateselection(selectinterface.refererselect)">
<option name="topreferer" value="nothing">view stats per referer</option>
{% for referer in refererlist %}
<option name="{{ referer }}" value="{{ referer }}">{{ referer }}</option>
{% endfor %}
</select>
</form>