Finding Values in an Array tutorial

Hi all,
Firstly im new to strings/arrays and dont erally get the difference, forgive me if i sound silly:stare:

i was looking at the tutorial [color=#003366]**Finding Values in an Array **[/color]here
and was wondering if i could replace

dataValues = [10,9,8,7,6,5,4,3,2]; 

with a string value thats is read from a text box eg,

dataValues = [myStringValue];

. myStringValue holds

"1,2,3,4,5,6,7"

and only finds it if i type in the full value, how do i get it to find each value seperatley after each comma? Everytime i try that it doesnt work correctly.

Could someone please help me out
Thanks