The code below shows a simple way to check if the name field only contains letters and whitespace. If the value of the name field is not valid, then store an error message:
$name = test_input($_POST["name"]);
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
PHP - Validate E-mail
The easiest and safest way to check whether an email address is well-formed is to use PHP's filter_var() function.
In the code below, if the e-mail address is not well-formed, then store an error message: