I/O Error

[saif.shakeel at gmail.com]

Hi,
    I am using File I/O to input an xml file form user and parse it.I
have used something like this:


file_input = raw_input("Enter The ODX File Path:")
odx_file_output = raw_input("Enter the output file path : ")
log_file_output = raw_input("Enter the path for LogFile  : ")

saveout = sys.stdout
try:
    f_open=open(odx_file_output, 'w')
except:
    print "cant open file"
    sys.exit()
sys.stdout = f_open

try:
    input_xml = open(file_input,'r')
except:
    print "The File Cannot Be Opened"
    sys.exit()

if input_xml.read(5)!='<?xml':
    print "Invalid File"
    input_xml.close()
    sys.exit()
else:
    xmldoc = minidom.parse(input_xml)
    input_xml.close()

if xmldoc.childNodes[1].getAttribute("DtdVers") == u'1.1.4' or
xmldoc.childNodes[1].getAttribute("DtdVers")== u'1.1.5':
    pass
else:
    print "Invalid Version"
    sys.exit()

                    After this some more code follows,but i have
pasted only the i/o part .when i run it in interactive mode(using
F5),first time it does fine,but second time it throws error like:

Traceback (most recent call last):
  File "C:\Projects\ODX Import\code_ini\odxparse.py", line 250, in
<module>
    file_input = raw_input("Enter The ODX File Path:")
ValueError: I/O operation on closed file

                        any idea what should be modified.
                                       Thx