Extract 200 words from one textarea and display

System

hi all,

My DCT code is look like this

<?xml version="1.0" standalone="no"?>
<!DOCTYPE data-capture-requirements SYSTEM "datacapture6.0.dtd">
<data-capture-requirements type="content" name="Lufth">
<ruleset name="Lufth">

<item name="summary">
<label>Summary</label>
<description>Enter the summary of the message.</description>
<textarea cols="50" rows="5" wrap="physical" />
</item>

<item name="sub">
<replicant min="1" max="5">
<item name="sun_heading">
<label>Sub heading.</label>
<description>Text describing the Section.</description>
<text required="t" size="30"></text>
</item>

<item name="paragraph">
<label>Paragraph</label>
<description>Enter the Description of the message.</description>
<textarea wrap="virtual" rows="10" cols="50" />
</item>
</replicant>
</item>
</ruleset>
</data-capture-requirements>

Requirement is, If user enter the text in a item name Paragraph, then Form API shd extract 200 words from the textarea and display in itemname summary textarea in same DCT.

as i tried with regex like : $ParsedPara =~ s/((\s+\S+){199}).*$/$1/; but couldn't able to extract in javascript.

Can any one provide me sample code for the following requirement. All suggestions and sample / code will be highly appreciated.

Thanks.