function dropdown(list){
var listElementStyle=document.getElementById(list).style;
if (listElementStyle.display=="none"){
listElementStyle.display="block";}
else {
listElementStyle.display="none";
}
}

function calcHeight()
{
  //find the height of the internal page
  var the_height=
    document.getElementById('listings_frame').contentWindow.
      document.body.scrollHeight;

  //change the height of the iframe
  document.getElementById('listings_frame').height=
      the_height;
}

function ajax_submit_form(form_id) {
    var action = $('#'+form_id+' form').attr('action');
    $.post(action, 
        $('#'+form_id+' form').serialize(),
        function(html) {
           $('#'+form_id).html( html );
        }
    );
    return false;
}