code: function(features) {
      
          var transaction = this.createElementNS(this.wfsns, 'wfs:Transaction');
          transaction.setAttribute("version","1.0.0");
          transaction.setAttribute("service","WFS");
          for (var i=0; i < features.length; i++) {
              switch (features[i].state) {
                  case OpenLayers.State.INSERT:
                      transaction.appendChild(this.insert(features[i]));
                      break;
                  case OpenLayers.State.UPDATE:
                      transaction.appendChild(this.update(features[i]));
                      break;
                  case OpenLayers.State.DELETE:
                      transaction.appendChild(this.remove(features[i]));
                      break;
              }
          }
          
          return OpenLayers.Format.XML.prototype.write.apply(this,[transaction]);
      }
docs: Method: write
  Takes a feature list, and generates a WFS-T Transaction
  
  Parameters:
  features - {Array(<OpenLayers.Feature.Vector>)}