document.write within a random number generator

To make a long story short.......... I created a random number generator for
my science fair project, and I am comparing its results to the results of
actually rolling dice, and a random number generator in Microsoft Excel.
Anyways my problem is that I want to display the numbers using a
document.write but I also want to count up the number of 1's, 2's, etc. Got
any advice?