Vaidating form input with PHP, for text only field

[peterggmss]

I need to know how to check if a variable contains text. I need it to contain only text and no numbers, but I can't figure out how with only PHP.

I have

code:

$surname = $_POST["surname"]; $first_name = $_POST["first_name"]; $street_address = $_POST["street_address"]; $phone = $_POST["phone"];

and use

code:

if($surname ==""){         $error = "You must provide a surname"; } if($first_name ==""){         $error = "$error <br>You must provide a first name"; } if($street_address ==""){         $error = "$error <br>You must provide a street address"; } if($phone ==""){         $error = "$error <br>You must provide a phone number"; } //Convert phone number to numbers (remove spaces, dashes, periods, etc.) //Takes numbers with alpha characters into consideration $phone = str_replace(array(' ', '-', '.', '(', ')', '!', '@', '#', '$', '%', '^', '&', '*', '_', '=', '+'), '', $phone); if ( strlen($phone) > 10 ){         $error = "$error <br>Your phone number cannot be more than 10 numbers"; } if(is_numeric($phone)==0){         $error="$error <br>The phone number must only contain numbers";

to make sure all fields have a value, and the phone number is only numbers.

But I can't use is_string() for the text fields ($surname and $first_name) because if it contains numbers it will still validate as TRUE (1).

Any advice?
Thanks!

[md]

you could always make a function that steps through a string and makes sure each character contains a letter... 'tis not a very difficult function to write either.

[PaulButler]

Regular expressions will do the trick:

code:

function text_and_spaces_only($str){ return preg_match('/[a-z ]+/i',$str); }

[Brightguy]

ctype_alpha($text) returns true if every character in $text is alphabetic.