Checking Strings

For security and common sense...

[inveni0]

I'd like to do some security and common sense checks on my site. The user submits a form that inserts their information into a database. I's like to make certain that the first name contains letters only, and the phone number numbers only.

So,

1) How do I check a string for letters only?
2) How do I check for numbers only?

I'm sure this is pretty standard, but I've never done it before. Any help is greatly appreciated.

[ahmedtheking]

ok mate, some nice reading for you, check out preg_match on php.net: [uk.php.net...]

[barns101]

Also, when inserting user-submitted data into a (presumably MySQL) database, remember to use mysql_real_escape_string [php.net].

[jatar_k]

try Character Type Functions [php.net]