How can I get a list of all values in select box?

You had two problems:

1) The order in which you included the HTML. Try changing the dropdown from “onLoad” to “no wrap – head” in the JavaScript settings of your fiddle.

2) Your function prints the values. What you’re actually after is the text

x.options[i].text; instead of x.options[i].value;

http://jsfiddle.net/WfBRr/5/