Howto monitor special changes at a website with nagios

i have to say, i really love to see the new htc amaze coming to europe.
to know, when this new phone will be available at t-mobile usa, i used my nagios
to monitor this ;-)

/usr/lib/nagios/plugins/check_http  -H www.t-mobile.com -u "/shop/Phones/cell-phone-detail.aspx?cell-phone=HTC-Amaze-4G-Black" -s "Coming Soon"


very simple ;)