Using plain javascript this is something that would work for you.
Now, I've assumed that you have at least some options in your select
html
<select id="selecty" multiple size=6 width=150 style="width:150px" name="ToLB" >
<option value="monkey">Monkey</option>
</select>
javascript
var listarray = new Array();
//NOTE: Here you used new as a variable name. New is a reserved keyword so you cant use that as a variable name.
var select = document.getElementById('selecty'); // get the select list
for(var i = 0; i < select.options.length; i++){
listarray.push(select.options[i].value);
}
console.log(listarray);
>> ["monkey"]
Fiddle here:
http://jsfiddle.net/mQH7P/