M1 sms captcha

from os import popen, system
from urllib import urlencode
from urllib2 import urlopen, Request
import sys

field_from = "sender_name"
field_contactno = ""
field_msg = ""
field_counter = 150-len(field_msg)

URL_BASE='http://msgctr.m1.com.sg/guest/'
# extract my JSESSIONID by loading a page from the site
set_cookie = urlopen(URL_BASE).headers.getheader("Set-Cookie")
sess_id = set_cookie[set_cookie.index("=")+1:set_cookie.index(";")]

# construct headers dictionary using the JSESSIONID
headers = {'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0.1) Gecko/2010010' \
'1 Firefox/4.0.1',
'Host':'msgctr.m1.com.sg',
'Referer':'http://msgctr.m1.com.sg/guest/index.jsp?notice=empty',
'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Language':'en-us,en;q=0.5',
'Accept-Encoding':'gzip,deflate',
'Accept-Charset':'ISO-8859-1,utf-8;q=0.7,*;q=0.7','Cookie':'JSESSIONID='+sess_id}

text = (urlopen(Request(URL_BASE+"index.jsp",headers=headers)).read())
for line in text.split("\n"):
    if "/guest/captcha.jpg" in line:
        line = (line.replace('<img src="','')).strip()
        position = line.find('"')
        captchaText = line[1:position].strip("guest/")
        sessionID = captchaText.strip("captcha.jpg?session=")

#save img
localFile = open('img.jpg', 'wb')
localFile.write(urlopen(Request(URL_BASE+captchaText,headers=headers)).read())
localFile.close()

#END-save img#
#img to text#
convert = system("convert  -contrast-stretch 12% -trim -depth 1 -colorspace Gray img.jpg ocr.tiff");
read = system("tesseract -psm 7 ocr.tiff result");
result = popen("cat result.txt", "r");
result = result.read()

result=(str(result).replace("\n","")).upper()
if(len(result)>3 or len(result)<3):
    sys.exit(1)
else:
    print "Captcha code is "+result
    # encode my POST parameters for the capcha page
    data = urlencode( {"from":field_from,"locale":"en",
        "msisdn":field_contactno,"msg":field_msg,
        "counter":field_counter,"sessionid":sessionID,"code":result} )
    # send captcha
    POST_URL = "http://msgctr.m1.com.sg/guest/processMessage.jsp?msisdn="+str(field_contactno.strip())
    #print POST_URL
    postOutput = urlopen(Request(POST_URL,headers=headers),data).read()
    if "notice=thankyou" in postOutput:
        print "SMS sent"
    else:
        print "Cannot read captcha.  Please retry"