how to access object property using variable [duplicate]

I have an object

var Messages = { 'fullName' : 'Tell us your cool name dude..! e.g. Yousuf Iqbal', 'userName' : 'Choose a catchy username. Remember! It should be available :)', 'password' : 'Choose a top secret password with special chars, numbers and alphabets', 'rePassword' : 'Retype the password you just typed. But, don\'t try to copy!', 'bYear' : 'Tell the year, in which this bomb blasted' }; 

and a variable..

var attribute = $('#userinfo form input').attr('name'); 

now i want to select Messages object property using this variable like this..

var message = Messages.attribute; 

but Its not working.. and have also tried the following..

var message = Messages+'.'+attribute;