def checkOrSaveUserModel(userModel):
# Use key_name attribute to get and create Model, otherwise, it maybe create two same Models.
userModel = UserModel.get_by_key_name(username)
if userModel:
errorMessages['occupiedUsername'] = '******' % username
else:
# Save new user with key_name attribute to make sure only one model will be inserted concurrently.
# import time
# time.sleep(5)
userModel = UserModel(key_name = username, username = username, email = email, password = password, ip = ip)
userModel.put()
