Error using tkinter

[JyotiC]

Hi,

I am making a gui, in which specifiction are taken from user, which are
wriiten to a file. and that file will bw executed.

finalstr is a string

   f = open('crossManual.sh','w')
   f.write(finalstr)
   f.close()

I am getting the error

        Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python2.3/lib-tk/Tkinter.py", line 1345, in __call__
    return self.func(*args)
  File "gui.py", line 248, in writescript
    f = open('crossManual.sh','w')
TypeError: an integer is required

Couldn't understand what it means
Plz tell me how to correct it.

Thanx in advance