Required library edition:
Required library file: dhtmlxgrid_ssc.js

store opene state of TreeGrid in cookie

• name - optional, cookie name
• cookie_param - additional parameters added to cookie

   mygrid.attachEvent("onOpenEnd", function(index,state){
          //minimal parameters set
          mygrid.saveOpenStates();
          //maximal parameters set
          mygrid.saveOpenStates("some_name","expires=Fri, 31-Dec-2010 23:59:59 GMT");
   });

This method is mutually exclusive with dynamic child nodes expanding.

See also: loadOpenStates