Ok, Im getting an error in this php code, MySQL response was
"mysql_num_rows(): supplied argument is not a valid MySQL result resource in ..site.. on line 195"

code

if(isadmin()) {
if($_POST['city']!='' || $_POST['zip']!='')
{
if($_POST['zip']!='')
$result = mysql_query("SELECT * FROM prerecycle WHERE zip='$_POST[zip]' ORDER BY zip");
else if($_POST['city']!='')
$result = mysql_query("SELECT * FROM prerecycle WHERE city='$_POST[city]' ORDER BY zip");}
}
else
{
if($_POST['city']!='' || $_POST['zip']!='') {
if($_POST['zip']!='')
$result = mysql_query("SELECT * FROM prerecycle WHERE zip='$_POST[zip]' AND show='1' ORDER BY zip");
else if($_POST['city']!='')
$result = mysql_query("SELECT * FROM prerecycle WHERE city='$_POST[city]' AND show='1' ORDER BY zip");}
}

--line 194--if(mysql_num_rows($result)!='')
--line 195--{
while($row = mysql_fetch_array($result))
{


I can't seem to find the error, help please?

here's a better version of the code --- http://img52.imageshack.us/img52/8043/codeq.png
Ok, i seem to get it --- but the error is here

if($_POST['zip']!='')
$result = mysql_query("SELECT * FROM prerecycle WHERE zip='$_POST[zip]' AND show='1' ORDER BY zip");
else if($_POST['city']!='')
$result = mysql_query("SELECT * FROM prerecycle WHERE city='$_POST[city]' AND show='1' ORDER BY zip");}

the AND show='1' part
is causing the mySQL error. If i remove it, then it work fine. is that syntax correct?