I am trying to add another option to the select drop-down, populated from a localStorage field. I haven't been successful. Here's my latest attempt:

<select size="1" name="testingSetup" id="testingSetup" onchange="document.formTesting.testingSetupLoad.value = this.value">
    <option value="">choose setup</option>
    <option value="setup 1">setup 1</option>
    <option value="setup 2">setup 2</option>
    <script type="text/javascript">
var aboutSetup1 = localStorage.getItem('aboutSetup1'); formTesting.testingSetup.value += "\n <option value=\""+aboutSetup1+"\">"+aboutSetup1+"</option>"
Google Chrome shows no errors, but it doesn't show the option, either. How do I populate a new option with a localStorage value with Javascript?