code: function(id, lonlat, contentSize, contentHTML, closeBox, closeBoxCallback) {
          if (id == null) {
              id = OpenLayers.Util.createUniqueID(this.CLASS_NAME + "_");
          }
  
          this.id = id;
          this.lonlat = lonlat;
  
          this.contentSize = (contentSize != null) ? contentSize 
                                    : new OpenLayers.Size(
                                                     OpenLayers.Popup.WIDTH,
                                                     OpenLayers.Popup.HEIGHT);
          if (contentHTML != null) { 
               this.contentHTML = contentHTML;
          }
          this.backgroundColor = OpenLayers.Popup.COLOR;
          this.opacity = OpenLayers.Popup.OPACITY;
          this.border = OpenLayers.Popup.BORDER;
  
          this.div = OpenLayers.Util.createDiv(this.id, null, null, 
                                               null, null, null, "hidden");
          this.div.className = this.displayClass;
          
          var groupDivId = this.id + "_GroupDiv";
          this.groupDiv = OpenLayers.Util.createDiv(groupDivId, null, null, 
                                                      null, "relative", null,
                                                      "hidden");
  
          var id = this.div.id + "_contentDiv";
          this.contentDiv = OpenLayers.Util.createDiv(id, null, this.contentSize.clone(), 
                                                      null, "relative");
          this.contentDiv.className = this.contentDisplayClass;
          this.groupDiv.appendChild(this.contentDiv);
          this.div.appendChild(this.groupDiv);
  
          if (closeBox) {
              this.addCloseBox(closeBoxCallback);
          } 
  
          this.registerEvents();
      }
docs: Constructor: OpenLayers.Popup
  Create a popup.
  
  Parameters:
  id - {String} a unqiue identifier for this popup.  If null is passed
  an identifier will be automatically generated.
  lonlat - {<OpenLayers.LonLat>}  The position on the map the popup will
  be shown.
  contentSize - {<OpenLayers.Size>} The size of the content.
  contentHTML - {String}          An HTML string to display inside the
  popup.
  closeBox - {Boolean}            Whether to display a close box inside
  the popup.
  closeBoxCallback - {Function}   Function to be called on closeBox click.