HTML dropdownlist value to XML in javascript
===

I would like to modify the values in the XML file with the dropdownlist value in HTML. I am using javascript language in my program.
After user click the submit button, the selected value in the dropdownlist should edit the value in the xml file.
Will greatly appreciate any help given.

                        <label for="Number of Tweets">Number of Tweets :</label></span>
                        <select id = "SelectResultsPerPage" class= "style8">

                        <option value = "10">10</option>
                        <option value = "20">20</option>
                        <option value = "30">30</option>
                        <option value = "40">40</option>
                        <option value = "50">50</option>
                        <option value = "100">100</option>
                        </select><br />
                        <br />

                        <button type=submit class="style6" id = "submit">SUBMIT</button>




                        
                        <?xml version="1.0" encoding="utf-8" ?>
                        <config>
                            <SelectResultsPerPage>20</SelectResultsPerPage>
                        </config>
