Determine Maximum For Scroll Top?

I'm storing the top scroll position in my grid and then when the grid is redrawn, I use setScrollTop to scroll back to that position.

However, in the case where the last row gets deleted, and I redraw the grid, I end up setting the Scroll Top to a value that leaves blank space at the bottom of the grid (where the deleted row used to be).

I was just wondering, is there a way to determine the maximum value that scrollTop should be set to - meaning, as if the scroll bar has been dragged all the way to the bottom.

It would be great if when setting scroll top, I could double-check to make sure I haven't exceeded the maximum.

I can live without this, but it would make the application I am writing look a little cleaner.

Thanks,
Alan