Please help.. javascript challenge

Hello,
I have one array with characters such as:
var array1 = {A,B,C,D,E,F }.
How to make a javascript function that takes us to every letter that is in the array list, two big letters and two small letters, that means a total of 4 letters.
In pageload Event It should appear 4 letters in one html table from function.
If a letter is "A" then we should hear a voice that says this is "A" letter.
For each page is refresh, the function must invert letters in the html table.
Thnx a lot