<?php

$db_list = mysql_list_dbs($dbcnx);



$counter[] = array();

if ($db_list) {
 echo '<input type = image src = "seldb.gif"><a href = "#" id = "linking">Выбрать БД</a>';
 echo '<select name = "database" onChange = "submit();">';

$i = 0;

 while ($row = mysql_fetch_object($db_list)){  
  echo '<option value = "'.$row->Database.'">'.$row->Database.'</option>';
  $counter[] = $row->Database; 
  $i++;
 } 

}

echo '</select><br>';

echo $counter['0'] ;

echo '<input type = submit value = "Выбрать" style = background-color:deepskyblue;color:white>';

?>

echo $counter['0'] ;

echo $counter[0] ;