.i want to export the data from pdf as RTF using script

When exporting data Acrobat will only include the raw text data, All formatting is lost. So if you want to preserver the formating you'll need to save it explicitly with a scirpt.

How this is done depends on the forms technology you're using and what it is that you want to do. For example, in an AcroForm Rich text is implimented with a series of Span objects, where each span has properties such as the font type, size, and color. The spans are accessed through the "field.richValue" property and can the converted to XML text with the "util.spansToXML()" function.

If this is a LiveCycle form then the RichText is formatted in a different way, it's already XML. RTF is really a very generic term. "RTF files" are different from RTF used in form fields.
If you need it in a different RTF format you'll probably have to write the code to convert it. However, depending on the enviroment this is operating in and what exactly you want to do there might be some other options.

Thom Parker
The source for PDF Scripting Info
[url=http://www.pdfScripting.com]pdfscripting.com[/url]

The Acrobat JavaScript Reference, Use it Early and Often
[url=http://www.adobe.com/devnet/acrobat/javascript.php]http://www.adobe.com/devnet/acrobat/javascript.php[/url]

Then most important JavaScript Development tool in Acrobat
[url=http://www.pdfscripting.com/public/34.cfm#JSIntro][b]The Console Window (Video tutorial)[/b][/url]
[url=http://www.acrobatusers.com/tutorials/2006/javascript_console][b]The Console Window(article)[/b][/url]