problem in appending a path to sys.path

[ketulp_baroda at yahoo.com]

Hi
I am having a problem in appending to sys.path
I am doing it this way:
>>> sys.path
['D:\\PYTHON23', 'D:\\PYTHON23\\Lib\\idlelib',
'D:\\WINNT\\system32\\python23.zip',
'D:\\PYTHON23\\lib\\site-packages\\Pythonwin',
'D:\\PYTHON23\\lib\\site-packages\\win32',
'D:\\PYTHON23\\lib\\site-packages\\win32\\lib',
'D:\\PYTHON23\\lib\\site-packages', 'D:\\Python23\\DLLs',
'D:\\Python23\\lib', 'D:\\Python23\\lib\\plat-win',
'D:\\Python23\\lib\\lib-tk', 'D:\\Python23']
>>> sys.path.append(r'D:\Python23\Lib\site-packages\code')
>>> sys.path
['D:\\PYTHON23', 'D:\\PYTHON23\\Lib\\idlelib',
'D:\\WINNT\\system32\\python23.zip',
'D:\\PYTHON23\\lib\\site-packages\\Pythonwin',
'D:\\PYTHON23\\lib\\site-packages\\win32',
'D:\\PYTHON23\\lib\\site-packages\\win32\\lib',
'D:\\PYTHON23\\lib\\site-packages', 'D:\\Python23\\DLLs',
'D:\\Python23\\lib', 'D:\\Python23\\lib\\plat-win',
'D:\\Python23\\lib\\lib-tk', 'D:\\Python23',
'D:\\Python23\\Lib\\site-packages\\code']

But when I close the shell and now again open it & do sys.path , it
doesnt show the path I last appended. i.e

>>> import sys
>>> sys.path
['D:\\PYTHON23', 'D:\\PYTHON23\\Lib\\idlelib',
'D:\\WINNT\\system32\\python23.zip',
'D:\\PYTHON23\\lib\\site-packages\\Pythonwin',
'D:\\PYTHON23\\lib\\site-packages\\win32',
'D:\\PYTHON23\\lib\\site-packages\\win32\\lib',
'D:\\PYTHON23\\lib\\site-packages', 'D:\\Python23\\DLLs',
'D:\\Python23\\lib', 'D:\\Python23\\lib\\plat-win',
'D:\\Python23\\lib\\lib-tk', 'D:\\Python23']

What am I doing wrong here??