im still new to ant and havent been able to get the tasks going,

error:
Buildfile: build.xml

init:

compile:
[javac] Compiling 14 source files to C:\Documents and Settings\x\Desktop\o2\build\WEB-INF\classes

create-db-tables:
[schemaexport] - Hibernate 2.1.2
[schemaexport] - hibernate.properties not found
[schemaexport] - using CGLIB reflection optimizer
[schemaexport] - Mapping file: C:\Documents and Settings\x\Desktop\o2\build\WEB-INF\classes\hibernateMappings\User.hbm.xml
[schemaexport] - Could not compile the mapping document
[schemaexport] net.sf.hibernate.MappingException: persistent class [o2.model.User] not found
[schemaexport] at net.sf.hibernate.cfg.Binder.bindClass(Binder.java:84)
[schemaexport] at net.sf.hibernate.cfg.Binder.bindRootClass(Binder.java:221)
[schemaexport] at net.sf.hibernate.cfg.Binder.bindRoot(Binder.java:1229)
[schemaexport] at net.sf.hibernate.cfg.Configuration.add(Configuration.java:249)
[schemaexport] at net.sf.hibernate.cfg.Configuration.addFile(Configuration.java:171)
[schemaexport] at net.sf.hibernate.tool.hbm2ddl.SchemaExportTask.getConfiguration(SchemaExportTask.java:195)
[schemaexport] at net.sf.hibernate.tool.hbm2ddl.SchemaExportTask.execute(SchemaExportTask.java:135)
[schemaexport] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:306)
[schemaexport] at org.apache.tools.ant.Task.perform(Task.java:401)
[schemaexport] at org.apache.tools.ant.Target.execute(Target.java:338)
[schemaexport] at org.apache.tools.ant.Target.performTasks(Target.java:365)
[schemaexport] at org.apache.tools.ant.Project.executeTarget(Project.java:1237)
[schemaexport] at org.apache.tools.ant.Project.executeTargets(Project.java:1094)
[schemaexport] at org.apache.tools.ant.Main.runBuild(Main.java:669)
[schemaexport] at org.apache.tools.ant.Main.startAnt(Main.java:220)
[schemaexport] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:215)
[schemaexport] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:90)
[schemaexport] Caused by: java.lang.ClassNotFoundException: o2.model.User
[schemaexport] at org.apache.tools.ant.AntClassLoader.findClassInComponents(AntClassLoader.java:1187)
[schemaexport] at org.apache.tools.ant.AntClassLoader.findClass(AntClassLoader.java:1128)
[schemaexport] at org.apache.tools.ant.AntClassLoader.loadClass(AntClassLoader.java:998)
[schemaexport] at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
[schemaexport] at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
[schemaexport] at java.lang.Class.forName0(Native Method)
[schemaexport] at java.lang.Class.forName(Class.java:141)
[schemaexport] at net.sf.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:86)
[schemaexport] at net.sf.hibernate.cfg.Binder.bindClass(Binder.java:81)
[schemaexport] ... 16 more
[schemaexport] - Could not configure datastore from file: C:\Documents and Settings\x\Desktop\o2\build\WEB-INF\classes\hibernateMappings\User.hbm.xml
[schemaexport] net.sf.hibernate.MappingException: persistent class [o2.model.User] not found
[schemaexport] at net.sf.hibernate.cfg.Binder.bindClass(Binder.java:84)
[schemaexport] at net.sf.hibernate.cfg.Binder.bindRootClass(Binder.java:221)
[schemaexport] at net.sf.hibernate.cfg.Binder.bindRoot(Binder.java:1229)
[schemaexport] at net.sf.hibernate.cfg.Configuration.add(Configuration.java:249)
[schemaexport] at net.sf.hibernate.cfg.Configuration.addFile(Configuration.java:171)
[schemaexport] at net.sf.hibernate.tool.hbm2ddl.SchemaExportTask.getConfiguration(SchemaExportTask.java:195)
[schemaexport] at net.sf.hibernate.tool.hbm2ddl.SchemaExportTask.execute(SchemaExportTask.java:135)
[schemaexport] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:306)
[schemaexport] at org.apache.tools.ant.Task.perform(Task.java:401)
[schemaexport] at org.apache.tools.ant.Target.execute(Target.java:338)
[schemaexport] at org.apache.tools.ant.Target.performTasks(Target.java:365)
[schemaexport] at org.apache.tools.ant.Project.executeTarget(Project.java:1237)
[schemaexport] at org.apache.tools.ant.Project.executeTargets(Project.java:1094)
[schemaexport] at org.apache.tools.ant.Main.runBuild(Main.java:669)
[schemaexport] at org.apache.tools.ant.Main.startAnt(Main.java:220)
[schemaexport] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:215)
[schemaexport] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:90)
[schemaexport] Caused by: java.lang.ClassNotFoundException: o2.model.User
[schemaexport] at org.apache.tools.ant.AntClassLoader.findClassInComponents(AntClassLoader.java:1187)
[schemaexport] at org.apache.tools.ant.AntClassLoader.findClass(AntClassLoader.java:1128)
[schemaexport] at org.apache.tools.ant.AntClassLoader.loadClass(AntClassLoader.java:998)
[schemaexport] at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
[schemaexport] at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
[schemaexport] at java.lang.Class.forName0(Native Method)
[schemaexport] at java.lang.Class.forName(Class.java:141)
[schemaexport] at net.sf.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:86)
[schemaexport] at net.sf.hibernate.cfg.Binder.bindClass(Binder.java:81)
[schemaexport] ... 16 more

my build.xml

<project name="o2" default="compile" basedir=".">
<property name="classes.dir" location="build/WEB-INF/classes/"/>
<property name="lib.dir" location="lib/"/>

<property name="src.dir" location="src/"/>
<property name="src.java.dir" location="${src.dir}/java/"/>
<property name="src.test.dir" location="${src.dir}/test/"/>
<property name="src.webapp.dir" location="${src.dir}/webapp/"/>

<property name="build.dir" location="build/"/>
<property name="build.java.dir" location="${build.dir}/java/"/>
<property name="build.test.dir" location="${build.dir}/test/"/>


<path id="classpath">
<fileset dir="${lib.dir}"/>
</path>


<target name="create-db-tables" depends="compile"
description="create database tables">
<taskdef name="schemaexport"
classname="net.sf.hibernate.tool.hbm2ddl.SchemaExportTask">
<classpath>
<path refid="classpath"/>
</classpath>
</taskdef>

<schemaexport quiet="no" text="no" drop="no" delimiter=";" output="create-tables.sql">
<fileset dir="${classes.dir}" includes="**/*.hbm.xml"/>
</schemaexport>
</target>


<target name="init">
<tstamp/>
<mkdir dir="${classes.dir}"/>
</target>

<target name="compile" depends="init">
<javac srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath" debug="on"/>

<copy todir="${classes.dir}">
<fileset dir="${src.java.dir}">
<exclude name="**/*.java"/>
</fileset>
</copy>
</target>

<target name="clean">
<delete dir="${build.dir}"/>
</target>

</project>

This has been answered many times on the forum.

Include your compiled classes in the classpath ie>