multi select fetch
HTML
<select id="filter" multiple="multiple">
<option>Yes</option>
<option>No</option>
</select>
<button id="button">button</button>
JavaScript
var list = document.getElementById("filter");
var button = document.getElementById("button");
button.addEventListener("click", function(e){
for(var i=0; i<list.length; i++){
if(list.options[i].selected) {
console.log(list.options[i]);
};
};
});