Warning: mail() [function.mail]: "sendmail_from" not set in php.ini or custom "From:" header missing in C:\xampp\htdocs\Test\registrationcheck.php on line 37

<?php
include('DB_connect.php'); //connect to database

$name = strip_tags($_POST['name']);
$email = strip_tags($_POST['email']);
$password = strip_tags($_POST['password']);
$repeat_password = strip_tags($_POST['repeat-password']);

//test to see if name only contains letters
if(!preg_match(("[^A-Za-z ]"),$name))
{
	//remember to make one for "too long name"
	
	//check if email in use
	
	$checkemailcommand="SELECT * FROM users WHERE email = '$email'";
	$checkemailresult = mysql_query($checkemailcommand);
	$num=mysql_num_rows($checkemailresult);

	if($num==0){
	
		//if passwords match up (should do it for email to but it ist done)
		 if($password==$repeat_password){
		 
			//we generate random code for confirmation email
			$confirm_code=md5(uniqid(rand()));
			
			//then we insert their info in a temporary database
			$insertinfocommand="INSERT INTO temp SET code='$confirm_code', name = '$name', email = '$email', password = '$password'";
			$insertinforesult=mysql_query($insertinfocommand);
			
			//if the info is succsesfully entered temp, we are going to send an email
			if($insertinforesult){
				
				$message = "Your Confirmation link: \r\n http://localhost/test/confirmation.php?passkey=$confirm_code";  //link to the confirmation page where the var passkey is the same as their code
				
				$sendmail = mail("$email","Redbook confirmation code","$message");
				
				echo "confirmation link have been sent to your email ".$email;
			}else{
			echo "couldn't find your email in our database";
			}
		 
		 		 }else{
		 echo "password doesn't match";
		 //header("Location:passworddoesntmatch.html")
		 }
		 
	}else{
	echo "email in use";
	//header("Location:alreadyregistered.html");
	}
	
}else{
echo "invalid name";
//header("Location:invalidname.html");
}



?>