Dynamic columns

[Pierre]

Hi all
I need to create datagrid columns "on the fly".
Here is what I have:

Code:

$.get("/json/members_tabs.json",
{
  }).done(function(data) 
{
  $('#member_invoice').datagrid({
  url:'/json/member_invoice.json',  
  columns: [[{field:"_date",title:"Date"},{field:"document",title:"Name"},{field:"shipping",title:"Price",align:"right"}]]  
  //columns: data
 });
});

my "data" contain same value as above, but it does not work.
Why not?
I mean, if I use this:
  columns: data
and inside "data" is this:
[[{field:"_date",title:"Date"},{field:"document",title:"Name"},{field:"shipping",title:"Price",align:"right"}]]
it will not work, and if I use this:
  columns: [[{field:"_date",title:"Date"},{field:"document",title:"Name"},{field:"shipping",title:"Price",align:"right"}]]
it works.

What I need to do so I can create columns on the fly?
I found this answer:
http://www.jeasyui.com/forum/index.php?topic=286.msg681#msg681
but it is same as above - If I use my data instead od "hardcoded" values - it does not work.
Thanks for help.

[stworthy]

Please check the data returned from '/json/members_tabs.json' to see if it is correct. Here is the example that create columns dynamically.
http://jsfiddle.net/H5rkg/

[Pierre]

Thank you for your solution, thanks a lot.