list box question

[Jam]

Here are a couple of fields that I want to pull info from.

field 1 field 2
jan 12
apr 15
jan 16
jan 15
apr 12
apr 16

In my form I have 2 combo boxes that have a drop down for
each field. I want to have a list that will pull the info
for all jan 12. So far I have a list box that when I
select a item from one of the combo boxes it will give a
list from either field (I.E. all jan or apr or all 12
ect.) with the needed info.