Using a 47 inch TV in addition to the onboard monitor with my P53E No

Last week I ran a class using our facilitiy's 47" HDTV with a HDMI input. Hooked my AZUS P53E Notebook to the TV via the HDMI cable and had video on both the notebook and the TV. Was able to conduct the class using the TV with me at my computer running the show.
Today I assisted our director to test the participation in a webinair next week using the same hookup I had above. Two things went wrong.
1. When I hooked up the TV the video on my notebook monitor quit. Got it back as soon as the TV was disconnected.
2. The resolution is way too low for the TV, 800x600 instead of higher, to get all of the content on the TV screen. The notebook monitor requires 1024X728. When I hook up the TV the resolution drops to the lower value of 800x600 and cannot be adjusted back up, it's grayed out.
Anything I should or can do to use the two monitors with better TV resolution?

Could you post your FULL model number for your laptop?

for Shawn C.,
It is an ASUSPRO ESSENTIAL P53E- XH31 Notebook SN: B8NXAS82469659 with Integrated Intel® HD Graphics 3000.