when i add a comment i get this warning - php

Question

hello guys i have a problem with this code
when id add a comment and comment insert in database
and when i make refresh on the same page i get this warning :
One of the fields are still empty,
i think the problem in the first code
<?php
if ($_POST['add'] and $_POST['add']=='comm'){
$comm_name =strip_tags($_POST['comm_name']);
$comm_country =strip_tags(mysql_real_escape_string($_POST['comm_country']));
$c =strip_tags(mysql_real_escape_string($_POST['comm']));
$comm_thread =strip_tags(mysql_real_escape_string($_POST['comm_thread']));
$status =$_POST['status'];
$getidtopic=$_GET['id_topic'];
$post_code=$_POST['post_code'];
if ($comm_name=='' or $comm_country=='' or $c=='' or $post_code=='' ){
echo "<script>alert(\"One of the fields are still empty
\");</script>";
}else if ($_POST['post_code']==$_SESSION['code']) {
$insertcomm=mysql_query("insert into comments values('','$comm_name','$comm_country','$comm','$comm_thread','$status') ")or die (mysql_error);
echo "<script>alert(\"your comment has been adding\");</script>";
}
}
?>
and this is the comment's form
<form action='' method='post' >
<table class='rightcol' width='100%' cellpadding='0' cellspacing='5'>
<tr>
<td colspan='3' id='addcomm'>add comm</td>
</tr>
<tr>
<td width='15%' ><div id='title_comm' value=''>name : </div></td>
<td ><input type='text' name='comm_name' value='<?if (!$insertcomm){
echo $comm_name;
}?>'/></td>
</tr>
<tr>
<td width='15%' ><div id='title_comm'>country </div></td>
<td ><input type='text' name='comm_country'
value='<?if (!$insertcomm){echo $comm_country;}?>'/>
</td>
</tr>
<tr>
<td valign='top' width='15%'><div id='title_comm'>comment : </div></td>
<td width='50%'>
<textarea cols='55' rows='12' name='comm'>
<?if (!$insertcomm){echo $c;}?>
</textarea></td>
<td valign='top' ><div id='note_comm'>
your comment will not insert if you try to use some thing bad
</div></td>
</tr>
<tr>
<td width='15%' ><div id='title_comm'><span style='color:red'>code : <br/>write these codes </span></div></td>
<td ><input type='text' name='post_code'/></td>
</tr>
<tr>
<td ><div id='code'>
<?php
$text=rand(400,80000);
echo $_SESSION['code']=$text;
?>
</div></td>
</tr>
<td colspan='4' ><input type='submit' name='addcomm' id='add' value='add comm'/></td>
</table>
<input type='hidden' name='comm_thread' value='<?php echo $getidtopic;?>' />
<input type='hidden' name='add' value='comm'/>
<input type='hidden' name='status' value='2'/>
</form>

Answer 1

that is because, when you refresh the page, the $_POST fields are reset, and the fields get empty, so when the page executes its PHP line if ($comm_name=='' or $comm_country=='' or $c=='' or $post_code=='' or $post_code=='' ){ it will find them to be empty.

Answer 2

You need to show us the table definition to better figure out what the issue is exactly. My guess is that your SQL statement is not properly prepared.