def getcellvalue (windowName, componentName, row, column = 0):
	""" returns the text in a cell at given row and column of a tree table
	INPUT: getcellvalue ('<window name>', '<component name>', '<row>', '<column>')

	OUTPUT: returns the string """
	try:
		_requestId  = str (random.randint (0, sys.maxint))
		_message = generatexml ('getcellvalue', _requestId, windowName, componentName, str (row), str (column))
		sendpacket (_message)
		_responseStatus, _responseData = getresponse (_requestId)
		if _responseStatus[0] != 0:
			raise LdtpExecutionError ('getcellvalue failed')
		return _responseData[1]
	except LdtpExecutionError, msg:
		raise LdtpExecutionError (str (msg))