Hi. I need a little help. I'm trying to work out how many combinations of characters there are for a string that is between 1 and 8 characters long and uses a-z (non caps) and 0-9. There are 36 useable characters and the string could be anything from simply 'a' to '99999999'. I was able to work out how many combinations there would be if there were known to be 8 characters in the string, but I'm not sure how to include all the combinations before that (1 - 7 characters long). Is there a formula for this? Thanks in advance!