Only allowing a Sortable to be dragged from and not dragged to

Only allowing a Sortable to be dragged from and not dragged to

I have 2 sortable columns. The first is a column with current issues and the second is a column with new issues. I only want to be able to drag from the second column to the first, but not from the first to the second.

I dynamically build the portlets in my code behind. Everything is working I just would like to "enhance" my application to not allow drag and drop from column 1 to column 2. I would like to be able to still drag and drop the first column, sort, etc..

Here is my JQuery: 
  1.       $(function () {           $(".column").sortable({               connectWith: ".column",               handle: ".portlet-header",               cancel: ".portlet-toggle",               placeholder: "portlet-placeholder ui-corner-all",               update: updatePortletPositions           }).disableSelection();           $(".portlet")       .addClass("ui-widget ui-widget-content ui-helper-clearfix ui-corner-all")       .find(".portlet-header")         .addClass("ui-widget-header ui-corner-all")         .prepend("<span class='ui-icon ui-icon-minusthick portlet-toggle'></span>");           $(".portlet-toggle").click(function () {               var icon = $(this);               icon.toggleClass("ui-icon-minusthick ui-icon-plusthick");               icon.closest(".portlet").find(".portlet-content").toggle();           });       });