how to disable submit button when value is not null

I am using table row to display records

Code:

echo '<tr>';                    
                   echo '<td align="center">'.$sno++.'</td>';
                   echo '<td>'.$row['doctype'].'</td>';
--Upload button --
 echo '<td>'.$row['status'].'</td>';

once images uploaded the status changed into 1.
if this all $row['status'] is null then disable submit button else 
enable.
need suggestion