将隐藏的HTML表单输入发送到PHP

I have been working on this for hours, and I haven't been able to get it right.

I am using jquery to pull <address> from an xml file. From there, I am using it to set that value to that of the hidden input. And from there, I would like to send the hmtl data to the .php file. I have tried everything I can think of and now it's 5:23AM.

Here is my HTML <input type="hidden" id="SenatorAddress" name="SA" />

Here is the JS: `

     {

        $('#StateSelect').change(function(){
            $('#SenatorSelect').empty();
            var state = $(this).val();
            var select1 = $('#SenatorSelect');
            var SAD = $('#SenatorAddress');
            select1.append('<option value="Select a senator">Select a Senator</option>');
        $(xml).find('member').each(function(){
            if(state == $(this).find('state').text()){
            var fname = $(this).find('first_name').text();
            var lname = $(this).find('last_name').text();
            select1.append("<option>"+fname+"&nbsp"+lname+"</option>");
            var sadress = $(this).find('address').text();
             SAD.append(Sadress);
        }

Here is the PHP:

The Honorable <?php echo $_GET["senatornames"]; ?><br>
<?php echo $_GET["SA"]; ?><br>
United States Senate<br />
Washington, DC 20510<br />

Use SAD.val(sadress) instead of SAD.append(Sadress);