“Unknown modifier 'g' in…” when using preg_match in PHP?
This is the regex I'm trying to use: /^(\w|\.|-)+?@(\w|-)+?\.\w{2,4}($|\.\w{2,4})$/gim I found it on this site , and it works great when I try it out there. But as soon as I place it in my code, I get this message: Warning: preg_match() [function.preg-match]: Unknown modifier 'g' in C:\xampp\htdocs\swebook\includes\classes.php on line 22 Can anyone explain what's wrong, and why it's working on that website and not in my code? codaddict There is no modifier g for preg_match . Instead, you have to use the preg_match_all function. So instead of: preg_match("/^(\w|\.|-)+?@(\w|-)+?\.\w{2,4}($|\.\w