I get nice picture on my 17" laptop.if i connect a large external tft monitor will i still get a nice picture?

Can i expect some deterioration of the picture?or do external monitors work ok?
Answer
There should be no reason why it doesnt work or be a bad picture. the quality of the output is dependant upon the operating resolution of the tft and the output from the laptop graphics card. i am running a laptop through a 22" samsung tft and a 37" lcd - no problems running at 1280x720