[php] email validation function

// http://scriptdemo.blogspot.ca // a simple way to check whether an email address is valid function CheckEmail($str) {    $str=str_replace('#','@',$str);    if (preg_match("/^[a-zA-Z]+([\._][a-zA-Z0-9]+)*@([a-zA-Z0-9]+\.)+[a-zA-Z]{2,4}$/",$str))     {       return TRUE;     }    else     {       return FALSE;     } }

people prefer something from php itself might be interested in filter_var

open sql database with php

<?php   // general information   $host="hostname";   $username="username";   $password="sqlpassword";   $db_name="databasename";   // connect to mysql   mysql_connect("$host","$username","$password") or die ("failed to connect server");   mysql_select_db("$db_name") or die ("failed to select db"); ?>