I have an array of 26 characters. I want three random values from the array, I use the following:
$rand_al = array_rand ($arralpha, 3);

Prob: I get the same characters each and every time.

What I am doing: First I seed the generator with
mt_srand ((double) microtime() * 1000000);

I fill my array $arralpha with values, and use the array_rand() function to return me random indexes
$rand_al = array_rand ($arralpha, 3);

On echoing the values at those indexes, I got the same values each time

Workaround: The way I am handling it right now is generating random values using mt_rand(0,25) 
and using those random values as the array subscripts. This method gives me random values.

Additional Info: mt_getrandmax() returned 2147483647.