function GetXML() {
  var ss = SpreadsheetApp.getActive();
  var sh = ss.getActiveSheet();
  var vals = sh.getDataRange().getValues();
  var tags = vals[3];
  var root = XmlService.createElement('Ads');
  root.setAttribute('formatVersion', '3')
  root.setAttribute('target', 'Avito.ru')
  root.setAttribute('__fvdSurfCanyonInserted', '1')

  for (var j = 4; j < vals.length; j++) {
    var child = XmlService.createElement('Ad')
    for (var k = 0; k < 21; k++) {
      if (vals[j][k] != "") {
         var child1 = XmlService.createElement(tags[k])
          .setText(vals[j][k]);
        child.addContent(child1)
      }
    }
    var Images = XmlService.createElement('Images')
    for (var k = 21; k < 31; k++) {
      if (vals[j][k] != "") {
        var child1 = XmlService.createElement('Image').setAttribute('url', vals[j][k])
        Images.addContent(child1)
      }
    }
    child.addContent(Images)
    root.addContent(child)
  }
  var document = XmlService.createDocument(root);
  var xml = XmlService.getPrettyFormat().format(document);
  Logger.log(xml);

}