the below code works but I get the below message every time?

<?php
mysql_connect(localhost,root,"";
mysql_select_db(prerentdb) or die( "Unable to select database"; 
$result=mysql_query($query); 
$num=mysql_numrows($result); 

$query = "INSERT INTO payhist (name,apt,amtpaid,rentdue,prevbal, 
hudpay,tentpay,datepaid,late,comments,paidsum) 
Select name,apt,
amtpaid,rentdue,prevbal,hudpay,tentpay,datepaid,late,comments,
paidsum From payments WHERE paidsum < rentdue OR late = 'L'"; 

$stat = mysql_query($query) or die('Query failed: ' . mysql_error() . " - query: $query";   
echo "data inserted</font>

";  
mysql_close(); 

?>  

Warning: mysql_numrows() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\hofiles\lateinsert.php on line 4
data inserted

By Resource it refers to the Connection Resources
which is $link=mysql_connect(xx,xx,xx); mysql_numrows(Bleep,$link); ta da and it will work but i advise to use OOP MYSQL

I was going to ask what was the error message the OP wanted!

Avoid hardcore coding and lean ActiveRecord (use framework)