Sorting an array of array

Hello, I am using php4 since few days, before I was in php3 Example : Let say I have a file called data containing this Gates Bill 10 Torvald Linus 10000 Black Joe 5 I put it in an array, with a key 1,2,3 My array is a array with two element inside, first is the key , second is another array with the data of each line 1 => Gates Bill 10 2 => Torvald Linus 10000 3 => Black Joe 5 Let's say I want to sort by third column and obtain 1 => Black Joe 5 2 => Gates Bill 10 3 => Torvald Linus 10000 Currently I did something very complex (using temp arrays) because in php3 only sort exists I though that php4 was able to do that easily, but I cannot see answer in the various sort functions in the documentation Anyone ? thanks in advance... dda