copying and inserting related records into 2nd table? error...

[bilis_money]

hi people

i'm trying to copy all the records that is related to my search.
my first table is 'topics',
and the 2nd table is 'topics_tmp'.

and the codes that producing an error is here below,
[code]
//Empty temporary table topics_tmp then fill again with contents from topic_rel[]
for($x=0; $x<=$total_rec; $x++){
//select records from table TOPICS first
$query  = "SELECT * FROM topics WHERE id='$topic_rel[$x]'";
$result = mysql_query($query) or die('Error, query failed');
$row = mysql_fetch_array($result, MYSQL_ASSOC);
$id_tmp = $row['id'];
$title_tmp = $row['title'];
$descrip_tmp = $row['description'];
$url_tmp = $row['url'];

//then insert selected data into TOPICS_TMP temporary table
$query = "INSERT INTO topics_tmp (id, title, description, url) VALUES ('$id_tmp', '$title_tmp', '$descrip_tmp', '$url_tmp')";
mysql_query($query) or die('Error, insert query failed');

}
[/code]

when i execute it the error message is showing up -->'Error, insert query failed'.
now what was my mistake here? am i doing the right copying from 1st table
and inserting the records into 2nd table?
Or do i have syntax error here?

Thank you very much in advance... for your kind help.

[bilis_money]

and by the way i am using 'topic_rel[]' an array as my temporary storage of all related topics. am i using it the right way?

thanks again.