REGEX in PHP forms

[Feebz]

I need a regex expression that verifies if a user inputs a valid name (letters and spaces only). However, it doesn't budge.

<?php  
	function validateInputs(){
		$status_form = "OK"; $msg="";
		$fname=$_GET['fname']; $lname=$_GET['lname'];
		$number=$_GET['number']; $subdivision=$_GET['subdivision'];
		$street=$_GET['street']; $districtcity=$_GET['districtcity'];
		$phonenum=$_GET['phonenum']; $cellnum=$_GET['cellnum'];
		if(!preg_match("/[^A-Za-z\s]/i", $lname)){
			$status_form="NOTOK";
			$msg .= "Name format is invalid. Use only alphabets and/or a dash<br>";
		}
		if($status_form!="OK"){
			while (list ($key, $val) = each ($_POST)) $pd .= "$key=".urlencode($val)."&";
			header ("Location: addentry.php?msg=$msg&$pd"); 
		} else return true;
	}
		
	if (array_key_exists('add_submit', $_POST)) {
		if (validateInputs()){
               
                }
		echo "New contact inserted. Details:<br />";
		echo "<b>FIRST NAME:</b> {$_POST['fname']}<br />";
		echo "<b>LAST NAME:</b> {$_POST['lname']}<br />";
		echo "<b>ADDRESS:</b> $addressstring<br />";
		echo "<b>MOBILE:</b> {$_POST['phonenum']}<br />";
		echo "<b>PHONE:</b> {$_POST['cellnum']}";
	} else echo "You can't see this page without submitting the form.";
?>