How to select one random element from the structure containing 2 integer array??

I have structure peer1 with 2 arrays value[] and age[], I want to select 1 random element from value array and store it in variable p. I need a help on this?

[Walter Roberson]

Replaced by later http://uk.mathworks.com/matlabcentral/answers/240758-how-can-i-select-random-element-from-one-of-the-array-in-structure