code: function () {
  
              var Connect = YAHOO.util.Connect,
                  oForm = this.form,
                  bUseFileUpload = false,
                  bUseSecureFileUpload = false,
                  aElements,
                  nElements,
                  i,
                  formAttrs;
  
              switch (this.cfg.getProperty("postmethod")) {
  
                  case "async":
                      aElements = oForm.elements;
                      nElements = aElements.length;
  
                      if (nElements > 0) {
                          i = nElements - 1;
                          do {
                              if (aElements[i].type == "file") {
                                  bUseFileUpload = true;
                                  break;
                              }
                          }
                          while(i--);
                      }
  
                      if (bUseFileUpload && YAHOO.env.ua.ie && this.isSecure) {
                          bUseSecureFileUpload = true;
                      }
  
                      formAttrs = this._getFormAttributes(oForm);
  
                      Connect.setForm(oForm, bUseFileUpload, bUseSecureFileUpload);
  
                      var postData = this.cfg.getProperty("postdata");
                      var c = Connect.asyncRequest(formAttrs.method, formAttrs.action, this.callback, postData);
  
                      this.asyncSubmitEvent.fire(c);
  
                      break;
  
                  case "form":
                      oForm.submit();
                      this.formSubmitEvent.fire();
                      break;
  
                  case "none":
                  case "manual":
                      this.manualSubmitEvent.fire();
                      break;
              }
          }
docs: Submits the Dialog's form depending on the value of the
  "postmethod" configuration property.  <strong>Please note:
  </strong> As of version 2.3 this method will automatically handle
  asyncronous file uploads should the Dialog instance's form contain
  <code>&#60;input type="file"&#62;</code> elements.  If a Dialog
  instance will be handling asyncronous file uploads, its
  <code>callback</code> property will need to be setup with a
  <code>upload</code> handler rather than the standard
  <code>success</code> and, or <code>failure</code> handlers.  For more
  information, see the <a href="http://developer.yahoo.com/yui/
  connection/#file">Connection Manager documenation on file uploads</a>.
  @method doSubmit