asp.net - How to handle unauthorised url redirect to error page -

in asp.net mvc 4 / mvc 5 how handle unauthorised url redirect error page. please 1 give suggestion

in check url xml file. xml file generate username or username int type.

public class logactionfilter:actionfilterattribute {    public override void onactionexecuting(actionexecutingcontext filtercontext)    {        bool access= log("onactionexecuting", filtercontext.routedata);        if (access == true)        {            //filtercontext.result=new redirectresult("~/user/not_assigned");            filtercontext.result = new redirecttorouteresult(            new routevaluedictionary             {                 { "controller", "error" },                 { "action", "error" }              });        }    }           private bool log(string methodname, routedata routedata)    {        var controllername = routedata.values["controller"];        var actionname = routedata.values["action"];        var message = string.format("{0} controller:{1} action:{2}", methodname, controllername, actionname);        int id = convert.toint32(httpcontext.current.user.identity.name);        xmldocument doc = new xmldocument();        string path=httpcontext.current.server.mappath("~/xmlfiles/"+id+".xml");        doc.load(path);        xmlnodelist nodes=doc.selectnodes("/modules/module");        foreach (xmlnode node in nodes)        {            xmlnodelist cnodes = node.childnodes;            foreach (xmlnode cnode in cnodes)            {                if (cnode.haschildnodes)                {                    foreach (xmlnode chnode in cnode.childnodes)                    {                        if (chnode.attributes["controller"].innertext.tostring().equals(controllername.tostring(), stringcomparison.invariantcultureignorecase) && chnode.attributes["action"].innertext.tostring().equals(actionname.tostring(), stringcomparison.invariantcultureignorecase))                        {                            string access = chnode.attributes["access"].innertext;                            if (access.equals("false", stringcomparison.invariantcultureignorecase))                            {                                return true;                            }                        }                    }                }                else                {                    if (cnode.attributes["controller"].innertext.tostring().equals(controllername.tostring(), stringcomparison.invariantcultureignorecase) && cnode.attributes["action"].innertext.tostring().equals(actionname.tostring(), stringcomparison.invariantcultureignorecase))                    {                        string access = cnode.attributes["access"].innertext;                        if (access.equals("false", stringcomparison.invariantcultureignorecase))                        {                            return true;                        }                    }                }            }        }           return false;    }     }