How to write script for service?

I have written a servic plugin as follows:

<plugin>  <service name="AM_Service_test">    <config>      <option name="script"            description="Test script"            default="/home/hyperic/agent/bundles/agent-4.5.1/pdk/scripts/test.sh"/>    </config>    <filter name="template"            value="exec:exec=sudo,file=%script%"/>    <metric name="Availability"            template="${template}:Availability"            indicator="true"/>    <metric name="Metric1"            category="PERFORMANCE"            template="${template}:x"            indicator="true"/>  </service></plugin>

I want just to test any value.

How the Shell Script has to look like?

How it can be written for Windows as Batch File?

Thanks for help.