regex help

[junebug]

i am trying to build a very simple regex and i am not sure what i am doing wrong. what i want it to do is check a variable to make sure it is all numbers. so this is the best i have come up with:

ereg("([A-Z|a-z])", $var);

so it checks for letters and if it's true i kill the script or false it continues. the problem is that there are other characters that could be entered. i have tried to make a regex that matches just numbers but can't seem to get it to work properly. i do not know how to make it match only numbers.

ereg("([0-9]+)", $var);

if only letters are entered, it works, but if letters and numbers are entered, it does not. i am still very new at regexs so any help would be great.

thanks in advance.

[Anon]

eregi_replace("[^{0-9]","",$var);}

will replace all non-numbers leaving you with a string of just numbers, you can then check that variable to see if it is empty or an acceptable value.

[cvincent]

Its right on this page:
http://www.phpbuilder.com/columns/dario19990616.php3?page=2

the regex is ^{(0|[1-9][0-9]*)$}

-Chris