Q:

PHP Regex add certain characters

I have the following regex that allows any letter and number (and I think uppercase too)! 
What I need is to allow certain characters such as a - value and only that. 
How would I insert that into this? 
$reg = preg_replace('/[^a-z0-9 ]/i', '', $reg);

A:

You can add additional characters inside the brackets like this:
$reg = preg_replace('/[^a-z0-9 \-]/i', '', $reg);

If you meant that you want the expression inside the brackets or a minus, you can use this:
$reg = preg_replace('/([^a-z0-9 ]|\-)/i', '', $reg);

Not tested, but I think thats it.