I need some tips on making this code cleaner..

[pneudralics]

I want to start focusing on making cleaner looking codes. How can I make the below look cleaner?

 

<?php
$ip = $_SERVER['REMOTE_ADDR'];

if (isset($_POST['submit'])) {
//Do some filtering
$email = mysql_real_escape_string(htmlentities(strip_tags(trim($_POST['email']))));
$name = mysql_real_escape_string(htmlentities(strip_tags(trim($_POST['name']))));
$password = mysql_real_escape_string(htmlentities(strip_tags(trim($_POST['password']))));
$confirmpassword = mysql_real_escape_string(htmlentities(strip_tags(trim($_POST['confirmpassword']))));

//If cookie is not set then we allow form to be submit
if (!isset($_COOKIE['registerform'])) {

if (!empty ($_POST['agree'])) {
if (!empty ($_POST['email'])) {		
	if (preg_match ('/^[A-Za-z0-9._]{1,100}@[A-Za-z0-9._]{1,100}\.[A-Za-z0-9]{1,100}$/', $email)) {
	//Check for duplicate emails
	$query = "SELECT * FROM user WHERE email = '$email' LIMIT 1";

	if ($result = mysql_query ($query)) {
		while ($row = mysql_fetch_array ($result)) {
		$emailcheck = $row['email'];
		}
	}

	if ($email != $emailcheck) {				
		if (!empty ($_POST['name'])) {
			if (preg_match ('/^[A-Za-z0-9\s]{1,50}$/', $name)) {		
				if (!empty ($_POST['password'])) {
					if (preg_match ('/^[A-Za-z0-9]{4,15}$/', $password)) {
						if (preg_match ('/^[A-Za-z0-9]{4,15}$/', $confirmpassword)) {		
							if (!empty ($_POST['confirmpassword']) && ($_POST['password']) == ($_POST['confirmpassword']) ) {					

							//Sha1 password
							$password2 = sha1($password);

							//Database insert
							$rquery = "INSERT INTO user (uniqueid, email, name, password, rip, lip, dateregistered, lastlogin) VALUES ('0', '$email', '$name', '$password2', '$ip', '$ip', NOW(), NOW())";

							if (mysql_query($rquery)) {
							//Set cookie to help prevent spam
							setcookie ('registerform', 'registerform', time()+60);

							//Create unique id
							$uniqueid = sha1($email);

							$uquery = "SELECT * FROM user WHERE email = '$email' LIMIT 1";

								if ($uresult = mysql_query ($uquery)) {
									while ($urow = mysql_fetch_array ($uresult)) {
									$uid = $urow['id'];
									}
								}								
							//New unique id = uniqueid+id
							$uniqueid2 = $uniqueid.$uid;

							$uquery = "UPDATE user SET uniqueid = '$uniqueid2' WHERE email = '$email' LIMIT 1";

								if (mysql_query($uquery)) {

								echo '<span style="color:#FF0000;font-size:11px">Thanks<br /></span>';
								}
								else {
								echo '<span style="color:#FF0000;font-size:11px">There was an error registering<br /></span>';	
								}								
							echo '<span style="color:#FF0000;font-size:11px">You have successfully registered</span>';
							}
							else {
							echo '<span style="color:#FF0000;font-size:11px">There was an error registering</span>';	
							}						

							} else {
							echo '<span style="color:#FF0000;font-size:11px">Your password and confirm password does not match</span>';	
							}
						} else {
						echo '<span style="color:#FF0000;font-size:11px">You have invalid characters in your confirm password</span>';	
						}
					} else {
					echo '<span style="color:#FF0000;font-size:11px">You have invalid characters in your password</span>';	
					}
				} else {
				echo '<span style="color:#FF0000;font-size:11px">Your password is empty</span>';	
				}
			} else {
			echo '<span style="color:#FF0000;font-size:11px">You have invalid characters in your name</span>';	
			}
		} else {
		echo '<span style="color:#FF0000;font-size:11px">Your name is empty</span>';	
		}				
	} else {
	echo '<span style="color:#FF0000;font-size:11px">Email duplicate</span>';	
	}	
	} else {
	echo '<span style="color:#FF0000;font-size:11px">You have invalid characters in your email</span>';	
	}		
} else {
echo '<span style="color:#FF0000;font-size:11px">Your email is empty</span>';
}
} else {
echo '<span style="color:#FF0000;font-size:11px">You must agree to the Terms</span>';
}
}
else {
echo '<span style="color:#FF0000;font-size:11px">You have already registered.</span>';	
}
}//End isset submit

?>

[Catfish]

Depending on how much data is in $_POST and whether the data needs 'filtering' as you call it, you could use a foreach loop to loop through $_POST and filter the data assigning it either to array values or I guess you could make seperate variables by using variable variable names (havent played around with them much). Any keys of $_POST that do not need filtering could be excepted using an exceptions array or even an exceptions list like: $exceptions = 'submit,agree'; Using a loop like this can also be reused in future scripts.

 

Other than that your code looks pretty neat to me.