I'm fairly new to Ant, but I've been through the docs and I can't seem
to address the problem I'm having.  Perhaps someone can help me.

I'm trying to create a path based on a conditional.  Basically, I want
to include certain things in my classpath if I'm on windows vs linux.

This is the standard classpath regardless of platform:
<path id="project.class.path">
   <pathelement location="${build.dir}"/>
   <fileset dir="${lib.dir}">
     <include name="*.jar"/>
   </fileset>
 </path>

This is my lovely conditional that I assume is setting the correct
property.  My tests indicate that this works.
<target name="osname" description="os test">
   <condition property="isLinux">
     <os name = "Linux"/>
   </condition>
   <condition property="isWindows">
     <os name = "Windows"/>
   </condition>
 </target>

These next two targets are where I would love to put in the dirty work
to fill out the classpath.
 <target name="ostest1" depends="osname" if="isLinux">
   <echo message="linux"/>
   <!-- Insert code here to add linux specific files to classpath -->
 </target>

 <target name="ostest2" depends="osname" if="isWindows">
   <echo message="windows"/>
   <!-- Insert code here to add windows specific files to classpath
-->
 </target>

This target, while empty, should give me a completed, correct for my
platform, classpath.
 <target name="ostestall" depends="ostest1, ostest2">

 </target>

I've tried just inserting the snippet below into the ostest* targets
with linux/windows in the appropriate slots, but it doesn't work as I
expected.  Basically, if I'm on linux, it always does the windows cp
even though the echo for ostest2 never comes out.  Can someone please
explain this and maybe point me in the direction of a fix?

<path id="project.class.path">
   <pathelement location="${build.dir}"/>
   <fileset dir="${lib.dir}">
     <include name="*.jar"/>
     <include name="linux/*.jar"/>
   </fileset>
 </path>