[Murdoc]

Hi, I'm making a script so that it can read in a file that has 2 numbers each line and break it down so they become usable data. I named n1 (number 1) and n2 (number2).

If I have a set of numbers:
eg:
N1 N2
12 4
14 2
2 5

and I wanted the computer to subtract N2 and N1 starting from the bigggest number (in this case, 14 and 2) how can I get it to determine which number is the biggest and subtract it with N2?

<!--------------MY PHP SCRIPT SO FAR-------------!>
<?php
$fp = fopen ("read.txt","r");
for ($y = 0; $y <=5; $y++) # Do this program 5 times
{
$rd = trim(fgets($fp,100));#the number that determines how many times file needs to be read
for ($x = 0; $x < $rd; $x++)
{
$fr = gets($fp,256); #reading the individual numbers
list ($n1,$n2) = explode (" ",$fr);
$An1 [$x] = $n1;#breaking down into an array for sorting and search
$An2 [$x] = $n2;# n2 array
rsort ($An1);
echo "
".$An1 [$x];
}
}
fclose($fp);
?>

<!-------------------TXT FILE CONTAINING DATA--------------!>
2
2 2
3 4
3
3 3
4 5
1 2
4
5 7
8 10
20 10
14 6
5
60 12
10 4
6 2
12 2
11 7
6
14 2
16 8
45 9
15 5
24 6
27 3