calss not found error in mapreduce program

calss not found error in mapreduce program

I am a beginer in mapreduce programming. I was executing a mapreduce
program in eclipse.While running a program am getting this error (i have
included commons-logging jar file)
Exception in thread "main" java.lang.NoClassDefFoundError:
org/apache/commons/cli/ParseException at
org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:59) at
org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79) at
org.apache.hadoop.streaming.DumpTypedBytes.main(DumpTypedBytes.java:142)
Caused by: java.lang.ClassNotFoundException:
org.apache.commons.cli.ParseException at
java.net.URLClassLoader$1.run(URLClassLoader.java:366) at
java.net.URLClassLoader$1.run(URLClassLoader.java:355) at
java.security.AccessController.doPrivileged(Native Method) at
java.net.URLClassLoader.findClass(URLClassLoader.java:354) at
java.lang.ClassLoader.loadClass(ClassLoader.java:424) at
sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at
java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 3 more
please help!! thanks in advance