jQuery/Json - Cannot convert 'data' to object -

i've simple ajax/json request jquery:

$.ajax({               type: "post",               url: "/some-json-url",               data: "score=" + 1,               datatype: 'json',               success: function(data){                 if(data.msg){                      alert(data.msg);                 }              }         }); 

however, if msg not set, gen error (looking through opera dragonfly):

unhandled error: cannot convert 'data' object

how can check if exists or not... in valid way?

if problem data being null can check so:

if(data && data.msg){     //... } 

or if have multiple properties, either this:

if(data){     if(data.msg){         //...     } } 

or return early:

if(!data)     return;  if(data.msg){     //... }