JSON format for jQuery UI Autocomplete

Moved the answer here from my comment:

[{"label":"mylabel","value":"myvalue"},...] 

I found it to be this format that .autocomplete is looking for for jquery UI 1.8

This is a JSON Format

{source: ["Milan", "Turin", "Venice", "Florence", "Rome"] }

or another source

{source: ["c++", "java", "php", "coldfusion", "javascript", "asp", "ruby"]}