Boot into Ubuntu from Windows and into Windows from Ubuntu

Question

I'd like to be able to boot into Windows from Ubuntu and into Ubuntu from Windows with grub.

Can I edit my /boot/grub/grub.cfg where there's the following:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
set default="3"

and only change from time to time the set default = "x" where x is the operating system on the grub list I want to boot on?

Is this going to work?