Remembered this info from a the dummies site.. :)

Genetic inheritance boils down to three simple concepts put forth by Gregor Mendel, a humble monk and part-time scientist who founded the entire discipline of genetics:

• Segregation: In diploid organisms, chromosome pairs (and their alleles) are separated into individual gametes (eggs or sperm) to transmit genetic information to offspring.

• Dominance: A dominant allele completely masks the effects of a recessive allele. A dominant allele produces the same phenotype in heterozygotes and in homozygotes.

• Independent assortment: Alleles on different chromosomes are distributed randomly to individual gametes.

Were you talking about the Punnett Square Calculator?  http://scienceprimer.com/punnett-square-calculator

But this may be the one you posted.  It may have an issue with Java or security but give it a try http://www.changbioscience.com/genetics/punnett.html

There is so much to learn about this stuff......