Support for AJAX and the XMLHttpRequest object
The BlackBerry® Browser introduced support for the XMLHttpRequest object in BlackBerry® Device Software version 4.6. You can use the XMLHttpRequest object to transfer data between the BlackBerry Browser and the web server without reloading the entire web page. You can use this object to send and retrieve XML, HTML, plain text, or other data types in the background. Because access to the DOM is also available, you can update the web page when new data or content is retrieved to create extremely responsive and dynamic web pages.
The XMLHttpRequest object can help to reduce the perceived latency that marks wireless browsing. Because requests are made in the background, the user can continue to work with the current web page while new data is retrieved. Because smaller amounts of data are parsed, the BlackBerry Browser can render modifications to the web page quickly.