function ajaxGetCoords() {

  var selectedSuburbNumeric = document.getElementById("suburb").selectedIndex ;
  var selectedSuburb        = document.getElementById("suburb").options[selectedSuburbNumeric].text ;

  var address = document.getElementById("street_details").value + ' ' + selectedSuburb + 'Victoria Australia' ;

    $.getJSON("googleMapCoordsToJSON.cgi",{ 'name' : address },function(data) {

      document.getElementById("latitude").value = data.lat;
      document.getElementById("longitude").value = data.long;

    }

  );

}