[jQuery] parent function value

[Ivan]

Hello,

I'm new in javascript and jquery, and i need little help.

function checkUsername(name) {

                            function checkUsername(name) {

                                                                         
$.post(prefix+'/registration/checkUsername',
{username:name.val()},function(data){if (data == 'yes'){name.addClass
('ui-state-error'); updateTips('Username taken'); return false} else
{return true} });
                            }

How can I set checkUsername to "true" or "false" from function(data)
which is communicating with my php code.

Thanks.