update mysql from php web page

I have an existing web page that pulls some data and displays it in form input fields. I would like to add the ability to edit those fields and submit the changes to the server, but have been unsuccessful. What bit of code do I need to add to the existing code? This is the existing code to display the info -- $query = "select * from warranty WHERE OwnerName='$result'"; $results = mysql_query($query); $row = mysql_fetch_array($results); I probably need to use if(isset($submit)): and an update statement, but my attempt just causes the web page to display completely blank. This is what I tried - if(isset($submit)): $query1 = "update warranty set VesselName='$vessel',OwnerName='$owner',OwnerStreet='$address',OwnerCity='$city',OwnerState='$state',OwnerZip='$zip',OwnerCountry='$country',DateInstalled='$DateInstalled',DealerName='$Dealer',DealerStreet='$DealerAddress',DealerCity='$DealerCity',DealerState='$DealerState',DealerZip='$DealerZip',DealerCountry='$DealerCountry',Model='$Parts',SN='$PartsSN',VesselType='$vesseltype',VesselLength='$length',InstalledOn='$construction',VesselTypeOther='$vesseltypeother') ; $result1 = mysql_query($query1); mysql_query($query1); else: $query = "select * from warranty WHERE OwnerName='$result'"; $results = mysql_query($query); $row = mysql_fetch_array($results); ?> What am I doing wrong? Thanks, -- Chip