WLST Invoke error

I am pretty new to weblogic 9.1 , infact I am using wlst for the first time. I
was trying to invoke it from the command line. So, I've set the environment and
invoked the following command java $classpath weblogic.WLST. It throws the
following error. Can you guys please let me know where I am making the mistake

Problem invoking WLST - Traceback (innermost last):
  File "<iostream>", line 14, in ?
java.lang.NoClassDefFoundError: javax/management/MBeanServerConnection
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:141)
        at
org.python.core.SyspathJavaLoader.loadClass(SyspathJavaLoader.java:70)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
        at org.python.core.Py.findClassEx(Py.java:636)
        at
org.python.core.SysPackageManager.findClass(SysPackageManager.java:115)
        at org.python.core.PackageManager.findClass(PackageManager.java:19)
        at
org.python.core.SysPackageManager.findClass(SysPackageManager.java:107)
        at org.python.core.PyJavaPackage.__findattr__(PyJavaPackage.java:143)
        at org.python.core.PyObject.impAttr(PyObject.java:756)
        at org.python.core.imp.import_next(imp.java:539)
        at org.python.core.imp.import_logic(imp.java:577)
        at org.python.core.imp.import_name(imp.java:621)
        at org.python.core.imp.importName(imp.java:635)
        at org.python.core.ImportFunction.load(__builtin__.java:1020)
        at org.python.core.ImportFunction.__call__(__builtin__.java:1013)
        at org.python.core.PyObject.__call__(PyObject.java:248)
        at org.python.core.__builtin__.__import__(__builtin__.java:973)
        at org.python.core.imp.importOneAs(imp.java:662)
        at org.python.pycode._pyx4.f$0(<iostream>:14)
        at org.python.pycode._pyx4.call_function(<iostream>)
        at org.python.core.PyTableCode.call(PyTableCode.java:208)
        at org.python.core.PyCode.call(PyCode.java:14)
        at org.python.core.Py.runCode(Py.java:1135)
        at
org.python.util.PythonInterpreter.execfile(PythonInterpreter.java:167)
        at
org.python.util.PythonInterpreter.execfile(PythonInterpreter.java:162)
        at
weblogic.management.scripting.utils.WLSTUtil.setupOffline(WLSTUtil.java:150)
        at
weblogic.management.scripting.utils.WLSTInterpreter.<init>(WLSTInterpreter
.java:86)
        at weblogic.management.scripting.WLST.main(WLST.java:50)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.jav
a:25)
        at java.lang.reflect.Method.invoke(Method.java:324)
        at weblogic.WLST.main(WLST.java:29)

java.lang.NoClassDefFoundError: java.lang.NoClassDefFoundError:
javax/management/MBeanServerConnection
 
Thanks.