Question

When someone selects a drop down list item, I want to redirect to the same page but with the query string set with

www.example.com/?somekey=selected-value

where selected-value is the numeric value of the option.

I am using jQuery if that makes it easier.

Answer 1

Use the onchange event in the select element:

<select ... onchange="window.location.href='?somekey='+$(this).val();">

Or if you want to hook it up using jQuery:

$(function(){
  $('#idOfTheSelect').change(function(){
    window.location.href = '?somekey=' + $(this).val();
  });
});