Sort of. When you are in a sitting position, your knees should be bent in by approx 30 degrees (ie, a 150 degree angle between your thigh and lower leg) when the pedal is at the lowest position. Then tweak in small increments till you find the sweet spot.
If you cannot raise your seat high enough, the problem is likely the seatpost. If you get a larger size, you'll also get a significantly larger reach, which is going to be very uncomfortable.
To put it in perspective - I have a 21" frame, which is on the larger size and which I have gotten to fit me due to careful selection of components (it was a well thought through process with advice from a specialist in order to fit my riding style). A normal 21" would be way too large, and a 22-23" would be ginormous. On a stock, typical-geometry bike, I feel happiest with a 20" frame or so.
Guadzilla, Rider of Base Mules and Reluctant Roadie Scum
"Numbers leads to motivation, motivation leads to suffering" - Jedi Master Cowzillahttp://www.vanditkalia.com