Index and match

Hello,
i am trying to get a machine number from an excel spread sheet by the following:

i have 3 columns

machine number machine plant
1 101 plant 1
2 102 plant 2
3 101 plant 3
4 102 plant 7
.
.
.

in the J7 and J8 cells i have:

machine plant

in J9
machine number

i need to be able to put a machine(i.e. 101) and plant(plant 3) into J7 and J8 and output the machine number that correlates to the specific machine plant combination(i.e. 3) into J9. there are machines in each plant with the same number, so i need to use the plant number and specific machine to find the specific machine number. i have used index/match, but don't know how to use BOTH J7 andJ8 to find the machine number that goes with both values.
please help