mySQL to JSON

Hey guys, on my server I´ve got a PHP file that retrieves my SQL database and encodes it to JSON:

<?php

	
	$host = "abc"; //Your database host server
	$db = "abc"; //Your database name
	$user = "abc"; //Your database user
	$pass = "abc"; //Your password
	$connection = mysql_connect($host, $user, $pass);
	//Check to see if we can connect to the server
	if(!$connection)
	{
		die("Database server connection failed.");	
	}
	else
	{
		//Attempt to select the database
		$dbconnect = mysql_select_db($db, $connection);
		//Check to see if we could select the database
		if(!$dbconnect)
		{
			die("Unable to connect to the specified database!");
		}
		else
		{
			$query = "SELECT * FROM cities";
			$resultset = mysql_query($query, $connection);
			$records = array();
			//Loop through all our records and add them to our array
			while($r = mysql_fetch_assoc($resultset))
			{
				$records[] = $r;		
			}
			//Output the data as JSON
			echo json_encode($records);
		}
	}
?>

Im currently developing and iOS app.. anyways.. i´ve populated my database with three objects.. so far so good.. everything works like a charm.. when i go to my php file that is online it shows correctly (as json).. but when i add more objects and update my php file that is online i only get a blank screen.. like it isn't encoding at all.. any ideas? is it just my slow internet server or could it be something else?? hope u understand what i mean :( thanks for now