I hope I can help you. I've only been a Flagstaff resident since 2001, so am not familiar with any property name changes prior to that.
Some more details, please:
Glass elevator- facing outdoors? Or inside?
What type of service center are you talking about? There is a question mark next to your words "service centre", so I'm not sure if there was a symbol there or if you meant for that to be there.
Do you recall what area of town it was in? What you might have been able to walk to from that point?
How many floors, approximately, in this hotel?
I don't have occasion to stay in a lot of hotels in my own city, as you can imagine, but have visited a few when friends or family come to town.
The properties I can think of right away which may fit are the
Embassy Suites Flagstaff (…hilton.com/en/…index.html)
Hampton Inn & Suites (…hilton.com/en/…index.html)
Radisson Woodlands Hotel: http://www.radisson.com/home/reservation/cityRateSearch.do?promotionalCode=&rateSearchForm.redemptionSearch=false&newSearch=true&city=Flagstaff&cityId=&country=&citySearchForm.countryAndState=US+AZ&rateSearchForm.checkinDate=11%2F15%2F2012&rateSearchForm.checkoutDate=11%2F16%2F2012&rateSearchForm.numberRooms=1&rateSearchForm.o%5B0%5D.a=1&rateSearchForm.o%5B0%5D.c=0&rateSearchForm.numberRooms=1&rateSearchForm.o%5B0%5D.a=1&rateSearchForm.o%5B0%5D.c=0&rateSearchForm.rmcCode=&rateSearchForm.crossBrandSearch=thisBrandOnly (the more I think about it, the more I think this might be the one. I would suggest checking recent reviews here on TA, though, as this property seems to be going downhill of late).
If none of the above seem to match up for you, please post back with as many details as you can recall. Or maybe someone else will remember it!
Edited: 12:13 pm, November 14, 2012