javascript - Collection2 validation context not working in Accounts.createUser -

i developing app in meteor. have customized registration form. using collection2 , simple schema client/server validation.

problem:- when write following code in client side it's shows me error of callback not function.

  accounts.createuser(newuser,{validationcontext: 'insertform'}, function(error,result){               if(!error){                   alert('yey');               }           }); 

error: typeerror: callback not function

account...506dd40 (line 151)

here helper code want store errors.

template.signup.helpers({     errors:function(){         var context = meteor.users.simpleschema().namedcontext('insertform');         return context.invalidkeys().map(function(data){ return {message: context.keyerrormessage(data.name)}});     } });