c# - Error in Saving of Regarding Attribute (Lead_PhoneCall Activity) from CRM Portal (2011)? -

i trying save guid of lead in regarding field of phonecall activity, gives error - "regardingobjectid" only. [on premise]

please help!

in new_phonecall.cs page :

phonecall_save.regardingobjectid = guid.parse(hdnfld_regarding.value); //(hdnfld_regarding hiddenfield in m passing guid, have taken along textbox)

in appcode/crmdmlibrary.cs :

    public class phoneentity     {        public guid regardingobjectid;     }      public bool savenewphonecall()     {         try         {             iorganizationservice context = crmdmlibrary.getcrmservice(url, domainname, username, password);              entity phone = new entity("phonecall");              phone["regardingobjectid"] = new entityreference("regardingobject", regardingobjectid);              guid phoneid = context.create(phone);             return true;         }         catch (exception ex)         {             httpcontext.current.response.write(ex.message);             httpcontext.current.response.end();             return false;         }      } 

passing regardingobject entityreference wrong.you should pass lead entityreference

 phone.attributes["regardingobjectid"] = new entityreference("lead", regardingobjectid); 

also check lead id coming from