$conn=mysql_connect('localhost','username','password');
$db=mysql_select_db("dbname",$conn);
if(!conn){
die("could not connect to server.."); }
if(!db){
die("could not connect to database.."); }

<form method=post action='thispage.php?insert=yes'>
insert into table: <input type='text' name='insert' size=30>
<input type=submit value=submit name='go'>

$insert=$_GET['insert'];
if($insert=yes){ mysql_query("INSERT field into table VALUES('')"); }

<form method=post action='submit.php'>
$user=$_SESSION['username']
//the session name of $user (in brackets) has to correspond with the $_SESSION[''] you
//are using for your user(login)
$userid=mysql_query("SELECT userid from usertable where username='$user'")
//adjust tablename to correspond with your usertable
Your comment: <input type='textarea' name='comment' cols='30' rows='10'>
Your rating: <select name='rating'><option value='0'>NONE</option><option value='10'>10</option><option value='9'>9</option><option value='8'>8</option><option value='7'>7</option><option value='6'>6</option><option value='5'>5</option><option value='4'>4</option><option value='3'>3</option><option value='2'>2</option><option value='1'>1</option></select>
<input type='hidden' name='userid' value=$userid>
<input type=submit value=submit name='go'>

<?php
$comment=$_POST['comment'];
$rating=$_POST['rating'];
$author=$_GET['userid'];
if(!$user || !$userid){
die("A problem occured when connecting to the database");
if(empty($comment) {
echo "Please write your comment";
}
if($rating==0){
echo "Please give a rating";
}} else {
mysql_query("INSERT INTO commenttable VALUES('$comment','$rating','$author')") or die("A problem occured when trying to post your comment");
}

if($rating['X'] { }

<textarea name=$textarea cols='10' rows='30'></textarea>
$textarea=htmlspecialchars($textarea,ENT_QUOTES);
$textarea=StrReplace($textarea,'<','>');
$textarea=StripSlashes($textarea);

<script language="javascript" type="text/javascript">
<!--
function intOnly(i) {
if(i.value.length>0) {
 i.value = i.value.replace(/[^\d]+/g, '');
}
}
//-->
</script>

Integer Only Textbox:<br>
<input type="text" onChange="intOnly(this);"
onKeyUp="intOnly(this);" onKeyPress="intOnly(this);">