Get data from XML - jscript - TESTCOMPLETE

I have same problem. I need change this value="0,20" to value="1,20" in

<configuration>
<deviceConfiguration>
<devices>

<add logicalName="MainScale" type="XXX.XXX.XXX.XXX.XXX, XXX.XXX.XXX">
    <parameters>
        <add key="CustomWeight" value="0,20"/>
    </parameters>
</add>

</devices>
</deviceConfiguration>
</configuration>

How can i get this value? Thank you so much for help!!!