How do you save to a user's Profile Fields using the Rest API?

Question

I have the following code in my ui.js file, but it is not saving as expected. I am using the line following line to save to the user's profile field. 
 data.ProfileFields['AccountType'] = $('input:checked', $(context.accountType)).val(); : 
 Here's more of the code: 
 _saveUser = function(context) {
 var data = {
 UserId : context.userId
 };

 if ($(context.accountType).length > 0)
 {
 data.ProfileFields['AccountType'] = $('input:checked', $(context.accountType)).val();
 }

 return $.telligent.evolution.put({
 url: $.telligent.evolution.site.getBaseUrl() + 'api.ashx/v2/users/{UserId}.json?IncludeFields=User.Id',
 data: data,
 dataType: 'json',
 defaultErrorMessage: context.saveErrorText,
 success: function(response) {
 $.telligent.evolution.notifications.show(response, {type:'success'});
 }
 });
 }, 
 
 Also, how do you retrieve the profile field in Velocity? I a trying the following 
 $user.ProfileFields.get_Item("AccountType").Value

Ben Tiedt · Accepted Answer

To save profile fields, post fields in the format "_ProfileFields_FIELDNAME", for example: 
 var data = {
 UserId : context.userId,
 _ProfileFields_AccountType: 'VALUE'
}; 
 To retrieve the value in Velocity, 
 #set($field = false)
#set($field = $user.ProfileFields.Get('AccountType'))
#if ($field && $field.Value != '')
 The value is $field.Value
#end