problem with Xupdate

[Titash Neogi]

Hello All,

I am facing a small problem with Xupdate. 

I have a xml file 

<maps>

<map>
<prereq></prereq>
<main></main>
<result></result>
</map>
.
.
.
</maps


I am populating this xml file from a form using Xupdate. Below is the
bit of code for this -
_______________________________________
let $updt:=  
	
	<xupdate:modifications version="1.0"
	          xmlns:xupdate="http://www.xmldb.org/xupdate" >    
	 <xupdate:append select="doc('/db/content/map1.xml ')/maps">    
      <xupdate:element name="map"></xupdate:element>       
	   </xupdate:append> 
	</xupdate:modifications> 

let $dummy:= xmldb:update($collection, $updt)

(: creates a new /map node in the xml file :)

(: update user inputs into /maps/map :)

            let $xupdate :=
                                        <xupdate:modifications
version="1.0"
 
xmlns:xupdate="http://www.xmldb.org/xupdate" >
                      <xupdate:append
select="doc('/db/content/map1.xml')/maps/map">
                                      <xupdate:element
name="prereq">{$prereq}</xupdate:element>
                                      <xupdate:element
name="main">{$main}</xupdate:element>
                                     <xupdate:element
name="resultt">{$result}</xupdate:element>
                                      
                      </xupdate:append>
                    </xupdate:modifications>
                                            
(: update the collection :)                                           

let $dummy2:= xmldb:update($collection, $xupdate)

_______________________________________


This works fine but the only problem is that every time it goes and
updates each map node with the content and also creates a new map node.


So if I had 

<maps>

<map>
<prereq>test </prereq>
<main>test2</main>
<result>test3</result>
</map>
.
.
.
</maps

And I input a new node

Prereq - tes5
Main - test6
Result - test7

The result is

<maps>

<map>
<prereq>test </prereq>
<main>test2</main>
<result>test3</result>

<prereq>test5 </prereq>
<main>test6</main>
<result>test7</result>

</map>
.
<map>
<prereq>test5 </prereq>
<main>test6</main>
<result>test7</result>

</map>
.
.
</maps



Is there a way in which I can add a new node and not change/add to the
existing nodes in the xml file?


Thanks and Regards
Titash