Sorry Screamer, I left the part where $available machines and $request_file_exists get updated. Before the code I had written, I check to see how many machines are available and put them in an array, as well as the $request_file_exists variable and as long as any of the two arrays are not empty (I left out the part where I use pop(@arrays) to update the variables) I keep going through the loop. But when I get to the last machine, it repeats its process twice. I update those variables in the "while" line. The code that I use to change the $variables is:

#start submitting jobs for the not_yet_run requests
while (( $usable_machine = pop(@$usable) ) && ( $request_file = pop(@a
+ll_requests) )){
#use the code I had before
}
[download]

Let me know what ya think Thanks