dbcon.php

<?php
//Connection Page
define("HOST", 'localhost');
define("USERNAME", 'db_user');
define("PASSWORD", 'db_password');

   mysql_connect( HOST, USERNAME, PASSWORD) or die("Could not connect");
   mysql_select_db ("chat2_db")or die('Cannot connect to the database because: ' . mysql_error());

//functions
function checkVar($var)
{
	$var = str_replace("\n", " ", $var);
	$var = str_replace(" ", "", $var);
	if(isset($var) && !empty($var) && $var != '')
	{
		return true;
	}
	else
	{
		return false;	
	}
}
function hasData($query)
{	$rows = mysql_query($query)or die("somthing is wrong");
	$results = mysql_num_rows($rows);
	if($results == 0)
	{
		return false;  
	}
	else
	{
		return true;  
	}
}
function isAjax()
	{
		if (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest' )
		{
	     	return true; 
		}	
		else
		{
			return false;
		}
		
	}

function cleanInput($data)
	{
		// http://svn.bitflux.ch/repos/public/popoon/trunk/classes/externalinput.php
		// +----------------------------------------------------------------------+
		// | Copyright (c) 2001-2006 Bitflux GmbH                                 |
		// +----------------------------------------------------------------------+
		// | Licensed under the Apache License, Version 2.0 (the "License");      |
		// | you may not use this file except in compliance with the License.     |
		// | You may obtain a copy of the License at                              |
		// | http://www.apache.org/licenses/LICENSE-2.0                           |
		// | Unless required by applicable law or agreed to in writing, software  |
		// | distributed under the License is distributed on an "AS IS" BASIS,    |
		// | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or      |
		// | implied. See the License for the specific language governing         |
		// | permissions and limitations under the License.                       |
		// +----------------------------------------------------------------------+
		// | Author: Christian Stocker <chregu@bitflux.ch>                        |
		// +----------------------------------------------------------------------+
		//
		// Kohana Modifications:
		// * Changed double quotes to single quotes, changed indenting and spacing
		// * Removed magic_quotes stuff
		// * Increased regex readability:
		//   * Used delimeters that aren't found in the pattern
		//   * Removed all unneeded escapes
		//   * Deleted U modifiers and swapped greediness where needed
		// * Increased regex speed:
		//   * Made capturing parentheses non-capturing where possible
		//   * Removed parentheses where possible
		//   * Split up alternation alternatives
		//   * Made some quantifiers possessive

		// Fix &entity\n;
		$data = str_replace(array('&amp;','&lt;','&gt;'), array('&amp;amp;','&amp;lt;','&amp;gt;'), $data);
		$data = preg_replace('/(&#*\w+)[\x00-\x20]+;/u', '$1;', $data);
		$data = preg_replace('/(&#x*[0-9A-F]+);*/iu', '$1;', $data);
		$data = html_entity_decode($data, ENT_COMPAT, 'UTF-8');

		// Remove any attribute starting with "on" or xmlns
		$data = preg_replace('#(<[^>]+?[\x00-\x20"\'])(?:on|xmlns)[^>]*+>#iu', '$1>', $data);

		// Remove javascript: and vbscript: protocols
		$data = preg_replace('#([a-z]*)[\x00-\x20]*=[\x00-\x20]*([`\'"]*)[\x00-\x20]*j[\x00-\x20]*a[\x00-\x20]*v[\x00-\x20]*a[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu', '$1=$2nojavascript...', $data);
		$data = preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*v[\x00-\x20]*b[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu', '$1=$2novbscript...', $data);
		$data = preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*-moz-binding[\x00-\x20]*:#u', '$1=$2nomozbinding...', $data);

		// Only works in IE: <span style="width: expression(alert('Ping!'));"></span>
		$data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?expression[\x00-\x20]*\([^>]*+>#i', '$1>', $data);
		$data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?behaviour[\x00-\x20]*\([^>]*+>#i', '$1>', $data);
		$data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:*[^>]*+>#iu', '$1>', $data);

		// Remove namespaced elements (we do not need them)
		$data = preg_replace('#</*\w+:\w[^>]*+>#i', '', $data);

		do
		{
			// Remove really unwanted tags
			$old_data = $data;
			$data = preg_replace('#</*(?:applet|b(?:ase|gsound|link)|embed|frame(?:set)?|i(?:frame|layer)|l(?:ayer|ink)|meta|object|s(?:cript|tyle)|title|xml)[^>]*+>#i', '', $data);
		}
		while ($old_data !== $data);

		return $data;
	}
?>