Problem comparing variables

Hi I am trying to compare 2 variables, but am having a problem.

I am using a mysql database to log promotion codes. There is a limit on the amount of times a paticular promotion code can be used.

I have a promotion code table, holding the promotion codes and the amount of times it can be used. I then have a promotion code log, which is logging the amount of times the promotion code has been used.

I want to compare the amount of times a promo code can be used to the number of rows returned from the promo code log.

In theory really easy but I am having a problem.

If i use the following code:

if ($use_limit >= $num) 

PHP:

it should run if the the limit is greater than or equeal to the amount of rows, but it doesnt, it returns false!

If i use the following code:

if ($use_limit == $num) 

PHP:

and change the rows in the database to match the limit it works.

So its something to do with the comparison operator i guess ($use_limit >= $num)

Am i doing somethign wrong here?

cheers

here is the entire code:

		else {
		
			$query = "SELECT * FROM multi_promo WHERE promo_code = '$promo_code'";
			
			$result = mysql_query($query);
			$num = mysql_num_rows($result);
			
			if ($num == '1') {	
			
				$sql = "SELECT * FROM multi_promo WHERE promo_code = '$promo_code'";
			
				$result = @mysql_query($sql,$connection) 
					or die(mysql_error());
					
					while ($row = mysql_fetch_array($result)) {
						$promo_code		= $row['promo_code'];
						$valid_from	 	= $row['valid_from'];
						$valid_to		= $row['valid_to'];
						$use_limit	 	= $row['use_limit'];
					}
			
				$sql = "SELECT promo_code FROM multi_promo_log WHERE promo_code = '$promo_code'";
				$result=mysql_query($sql);
				$num=mysql_num_rows($result);
			
				if ($use_limit >= $num) {
				
				$sql = "INSERT INTO multi_promo_log SET
				promo_code = '$promo_code'";
					
				$result = @mysql_query($sql,$connection) or die(mysql_error());
				
				$sql = "INSERT INTO transaction SET
				name  			= '$_POST[name]',
				email			= '$_POST[email]',
				contact 		= '$_POST[contact]', 
				serv_lgth		= '$_POST[serv_lgth]',
				contract		= '$_POST[contract]', 			
				dl_url		    = '$uploadpath$filename', 
				item_no			= '$item_no',
				product			= '$product',
				price			= '$price',
				date			= 'CURDATE()',
				quest			= '$_POST[quest]'";
					
				$result = @mysql_query($sql,$connection) or die(mysql_error());
				$invoice_no = mysql_insert_id();
				
				header("Location: promo_test.php?invoice_no=$invoice_no&name=$_POST[name]&email=$_POST[email]&contact=$_POST[contact]&serv_lgth=$_POST[serv_lgth]&contract=$_POST[contract]&st=Completed");
				}
			else
				{
				header("Location: ../promo_error.php?error=This promo has been used more than the limit");
				}
		}
		else {header("Location: ../promo_error.php?error=This promo has less than one line in the db");}
	}

PHP:

 

Variable scope. You need to declare the use_limit variable BEFORE you enter any conditional statements, loops or functions.