Compiling with external JARs using Eclipse

Question

I've spent 3 days on this and I still don't seem to be any nearer solving the problem. I am using a couple of external JAR files within my project and everything is working fine within the IDE, it's when I come to compile my own JAR that I'm having problems. I've tried created my JAR by choosing file->export, but it doesn't seem to pull in the external JARs. My class paths must be correct as I can run it within the IDE, but I'm missing something.
Next I discovered ANT and had a play with that. After some toil I got it to generate a JAR, but it has two problems. 1. The manifest file cannot be found, but let's forget about that for now, as I haven't really looked into it. 2. The generated JAR is only 250Kb, when (if the external JARs are packaged with it) it should be closer to 5Mb. Again I've set my class paths in the External Tools dialog, but still nothing.
Could someone please try and point me in the right direction. I've even spent a couple of hours at Borders reading up on ANT and Eclipse, that where my ANT script came from, but it hasn't got me the result I need. If it's any help my build.xml is below
<?xml version="1.0" encoding = "UTF-8"?>
<project name="C_G" default="Main Build" basedir=".">
    <property name="bin" location="bin"/>
    <property name="src" location="."/>
    <property name="jardir" location="${bin}/lib"/>
    <property name="jarfile" location="${jardir}/c_g.jar"/>
    <property name="build.compiler"
    value="org.eclipse.jdt.core.JDTCompilerAdapter"/>
    <target name="Main Build" depends="Initialize, Compile, Jar">
        <echo message="Ant Building"/>
    </target>
    <target name="Initialize">
        <delete dir="${bin}"/>
        <delete dir="${jardir}"/>
        <mkdir dir="${bin}"/>
        <mkdir dir="${jardir}"/>
    </target>
    <target name="Compile" depends="Initialize">
        <javac srcdir="${src}"
            destdir="${bin}">
        </javac>
    </target>
    <target name="Jar" depends="Initialize, Compile">
        <jar destfile="${jarfile}" basedir="${bin}"/>
    </target>
</project>

Answer 1

Damn it, so I do have to tackle the 'manifest not
found problem' first then. I would have though
Eclipse would have made a better job at making the
manifest file.All I can say: RTFM. This is not an Eclipse support forum. Maybe it does, and you use some incorrect settings.
I just placed it into the root of the JAR, but when I
run it can't find itIt doesn't belong there. It goes into a directory named META-INF