javascript check numeric

isNaN(value)

javascript simple email validation

var filter = /[\w-]+@([\w-]+\.)+[\w-]+/;

if (!filter.test(email)) {
alert('Please enter a valid email address');
}

javascript get form element

<script language="javascript">

function validate_form() {

var username = document.forms['register'].elements['user_username'].value;
var password = document.forms['register'].elements['user_pass'].value;
var name = document.forms['register'].elements['user_name'].value;
var email = document.forms['register'].elements['user_email'].value;
var phone = document.forms['register'].elements['user_phone'].value;

}
</script>

<form name="register" method="post" action="register.php">
<table>
<tr><td>Username</td><td>: <input type="text" name="user_username"></td></tr>
<tr><td>Password</td><td>: <input type="text" name="user_pass"></td></tr>
<tr><td>Name</td><td>: <input type="text" name="user_name"></td></tr>
<tr><td>Email Address</td><td>: <input type="text" name="user_email"></td></tr>
<tr><td>Phone number</td><td>: <input type="text" name="user_phone"></td></tr>
<tr><td colspan="2" align="center"><input type="Button" onClick = "validate_form()" value="Register"></td></tr>
</table>
</form>

php sql query and fetch results

$sql = "SHOW TABLES FROM $dbname";
$result = mysql_query($sql);

while ($row = mysql_fetch_row($result)) {
    echo "Table: {$row[0]}\n";
}

php include file

<?php include("conn.php"); ?>

php testing on database connection

<?php
if (!mysql_connect( 'localhost', 'root', '')) {
    echo 'Could not connect to mysql';
    exit;
}

$dbname = 'demo';
$sql = "SHOW TABLES FROM $dbname";
$result = mysql_query($sql);

if (!$result) {
    echo "DB Error, could not list tables\n";
    echo 'MySQL Error: ' . mysql_error();
    exit;
}

while ($row = mysql_fetch_row($result)) {
    echo "Table: {$row[0]}\n";
}

mysql_free_result($result);
?>

php connect database

<?php
$link_identifier = mysql_connect('localhost', 'root', 'password');
mysql_set_charset('UTF8', $link_identifier);
mysql_select_db("database name");
?>