code: function(evt) {
          var code = evt.keyCode;
          
          // check for delete key
          if(this.feature &&
             OpenLayers.Util.indexOf(this.deleteCodes, code) != -1) {
              var vertex = this.layer.getFeatureFromEvent(this.handlers.drag.evt);
              if (vertex &&
                      OpenLayers.Util.indexOf(this.vertices, vertex) != -1 &&
                      !this.handlers.drag.dragging && vertex.geometry.parent) {
                  // remove the vertex
                  vertex.geometry.parent.removeComponent(vertex.geometry);
                  this.layer.events.triggerEvent("vertexremoved", {
                      vertex: vertex.geometry,
                      feature: this.feature,
                      pixel: evt.xy
                  });
                  this.layer.drawFeature(this.feature, this.standalone ?
                                         undefined : 'select');
                  this.modified = true;
                  this.resetVertices();
                  this.setFeatureState();
                  this.onModification(this.feature);
                  this.layer.events.triggerEvent("featuremodified", 
                                                 {feature: this.feature});
              }
          }
      }
docs: Method: handleKeypress
  Called by the feature handler on keypress.  This is used to delete
  vertices. If the <deleteCode> property is set, vertices will
  be deleted when a feature is selected for modification and
  the mouse is over a vertex.
  
  Parameters:
  evt - {Event} Keypress event.