Using em-dashes in conjuction with commas

[snoopy13a]

These people are wrong. In the age of typewriters, two spaces was correct when typing due to fixed-width characters. Two spaces in books has never been correct. In modern computing, where Word is capable of emulating a book's careful typesetting automatically, a space is not a fixed width character, and is automatically adjusted for optimal texture. Putting in two spaces leaves huge, gaping holes in body copy, because you're ordering the program to add in a second helping of an already inflated character.

What if you're using Courier?

Ha, what am I saying. Everyone uses 12 point Times New Roman . . .