An asynchronous postback behaves much like a synchronous postback, but performance is enhanced by minimizing the content requested from the server and rendered again in the client browser. The rest of the page remains unchanged, therefore data traffic and page flickering are significantly reduced.
The AJAX enhancement is transparent to PowerBuilder developers. To use the AJAX feature, you do not need to learn anything new or change your PowerScript code.
PowerBuilder cannot deploy the Web Forms application unless AJAX is installed on the Web server. You can download and install the Microsoft ASP.NET AJAX Extensions version 1.0 on both the development and deployment computers from the ASP.NET Web site at http://www.asp.net/ajax/downloads/archive .
For information on how Web Forms applications work with AJAX extensions, see the chapter on "Overview and Configuration of .NET Targets" in the Deploying Applications and Components to .NET book.
Using synchronous update functionality If you must use synchronous update functionality, you can change the PBPostbackType global property to "Synchronous" in the Web.config file that PowerBuilder creates when you deploy your Web Forms application. However, support for synchronous update functionality will be removed in future releases of PowerBuilder and you cannot modify the PBPostbackType property in the PowerBuilder IDE.
For information on global properties, see the chapter on "Properties for .NET Web Forms" in the Deploying Application and Components to .NET book. For information on modifying the Web.config file, see the section on "Viewing and modifying global properties in IIS Manager" in the same book.