substr?

Hi all, Is this right? It seems to me that substr is working in reverse? $string = "1234567890"; // Always numerical, always 10 chars. if (!substr($string, 0, -7) == "083") { echo "not 083\n"; } else { // Exists here. echo "is 083\n"; } Due to the reverse if, shouldn't it exit not 083? I'd just like to get some clarity on this, allot of my work depends on validating these numbers *correctly*.... Basically, I want to see if the first three characters is 072, 073, 082, 083, or 084. If not, the $string must be discarded. I've also tried if(substr($string, 0, -7) != "083"), but that also doesn't work.... ereg(*) also doesn't seem to be able to search for patterns only on the beginning of a string, so even if I wanted to use a ereg expression, I'd have to cut the first 3 chars from the string with substr first? How can / should I validate these numbers?