<script>
$("#addline1").change(function() {
  var itemVal = $.("#addline1").val();
  var dataString = "companyid=" + companyid + "&addline1=" + itemVal;
  processChange(dataString);
});

function processChange(dataString){

  $.ajax({
    type: "POST",
    url: "../inc/dataforms/test.php",
    data: dataString,
    complete: function(data) {
      var Resp = data.responseText;
      console.log(Resp);
    });
  });
});
</script>

mysqli_query($dbc,"UPDATE `comp_companies`  SET `regoffice1` = '$_POST[addline1]'
WHERE `company_id` = '$_POST[companyid]'");

$("#addline1").change(function() {
        var itemVal = $.("#addline1").val();
        var dataString = "companyid=" + companyid + "&addline1=" + itemVal;
        processChange(dataString)
        });