I have Ext.grid.Grid component, which get a list of users from JSON script.
When i dblclick on row with user user edit BasicDialog is opened.
That is working right.

Now I want to fill form fields of that BasicDialog with data, which I want to recieve from another JSON script.
How can I do it? I'm using Ext-1.0-alpha2.
Documentation doesn't contain any info about Ext.data.Store, Ext.data.DataReader, Ext.data.JsonReader and so on.