Help understanding entry validation.

[Drewdle]

I'd like some help understanding how to use validation for form field characters please!

 

if(!preg_match("/^[a-zA-Z]+$/",$_POST['fname']))
{
echo "Invalid Entry";
}

 

Now, where do I specify what characters to check? Is it this part:

 

("/^[a-zA-Z]+$/",$_POST['fname'])

 

How would I add other things? I believe that allows upper and lower case letters only, how would I add things like '@' '-' '_' etc etc...would I just add them to the list inside the square brackets or is it a new set of brackets?... What about numbers? Would it be "/[0-9]/" ?

 

Also, can I swap $_POST['fname'] with just a plain variable ($fname)?.

 

(oh and does it need the '/' inside each quote?)

 

Thanks!

 

OH and also! if I was to check several fields, and if all is ok execute a script would I need to have elseif/else statements of could I have a new if statement for each and then just run the script below it?

 

Thanks again!

[BlueSkyIS]

http://www.google.com/search?client=safari&rls=en&q=php+regular+expressions&ie=UTF-8&oe=UTF-8

[Drewdle]

I've read most of them...it confuses me a bit.

[Pikachu2000]

As a rule, if you can use string functions instead of regex patterns, it's preferable to do so.