title: Backbonejs event occurring multiple times
body: <p>I have a view that displays items in a grid.  If a button to create a new row is clicked, a popup window (use SimpleModal) is displayed to allow the user to save the row to the server.  If all goes well, the window closes and the grid is refreshed.  All works fine up to this point.  If I now open the window a second time, the save record event will get called two times.  If I close and open the window a third time, then the event will be called three times, etc.  I have no idea why the event is getting rebound multiple times.  Here are my two views:</p>
  
  <p>FieldList View:</p>
  
  <pre><code>var fieldListView = Backbone.View.extend({
  el: "#centerbodycontent",
  initialize: function () {
      _.bindAll(this, 'render', 'addField');
  },
  
  render: function () {
      $(this.el).empty();
      $("#FieldGridTemplate").tmpl({ results: this.model }).appendTo(this.el)
      stripe($(this.el).find("tbody"));
      return this;
  },
  events: {
      "click a#addfield": "addField"
  },
  addField: function (e) {
      window.appController.popup = new fieldFormView({ model: new fieldModel({ contenttype_id: this.model.id }) });
      window.appController.popup.render();
  }
  </code></pre>
  
  <p>});</p>
  
  <p>Form View (this is what gets called for the popup)</p>
  
  <pre><code>var fieldFormView = Backbone.View.extend({
  el: "#popupwindowcontent",
  
  events: {
      "click #savefieldandnew": "savefield",
      "click #savefieldandclose": "savefield",
      "change input,textarea,select": "changeField"
  },
  render: function () {
      var formWrapper = $(this.el).find(".modal-form")[0];
      $(formWrapper).empty();
      $("#FieldFormTemplate").tmpl({ results: this.model }).appendTo(formWrapper)
      OpenForm(this.el, "Add Field", 450, 600);
      return this;
  },
  // automatically updates the model during field changes
  changeField: function (e) {
      var changeobj = new Object;
      switch (e.target.type) {
          case "radio":
              changeobj[e.target.id] = parseInt($(e.target).val());
              break;
          case "checkbox":
              changeobj[e.target.id] = $(e.target).is(":checked");
              break;
          default:
              changeobj[e.target.id] = $(e.target).val();
              break;
      }
  
      if (e.target.id.toLowerCase() == "name") {
          var k = $(this.el).find("#key");
          if (jQuery.trim(k.val()).length == 0)
              k.val($(e.target).val().replace(/[^a-zA-Z0-9]+/g, '').toLowerCase());
  
          var l = $(this.el).find("#label");
          if (jQuery.trim(l.val()).length == 0)
              l.val($(e.target).val());
      }
  
      var options = { silent: true };
      this.model.set(changeobj, options);
  },
  savefield: function (e) {
      var kcode = (e.which);
      var thiz = this;
      var m = this.model;
      var nextaction = e.target.id;
      alert(nextaction);
      if (kcode == 0 || kcode == 1 || kcode == 32) {
          e.preventDefault();
          if ($("#contentfieldform").validate({
              rules: {
                  name: { required: true },
                  label: { required: true },
                  key: { required: true }
              }
          }).form()) {
              m.save(null, {
                  headers: { "If-Match": m.get("version") },
                  error: function (model, response) {
                      var errResp = JSON.parse(response.responseText);
                      popupException("Content Type Modification Error", errResp.errors[0].message);
                  },
                  success: function (model, response) {
                      window.appController.popup.model = new fieldModel;
                      $.pnotify({
                          pnotify_title: 'Field Saved',
                          pnotify_text: 'The field was saved successfully.'
                      });
  
                      if (nextaction == "savefieldandclose") {
                          $.modal.close();
                      }
                  }
              });
          }
      }
  }
  </code></pre>