php mysql select dropdown selected and distinct query

[MIAsunsh]

I am confused here.\[code\]$sql_n = mysql_query("SELECT * FROM table1 WHERE n='{$row['n']}'");$row_n = mysql_fetch_array($sql_n);$sql= mysql_query("SELECT DISTINCT p FROM table1");while($row = mysql_fetch_array($sql)) { if($row['p'] == $row_n['p']) { $selected = " selected"; } $np .= "<option value='http://stackoverflow.com/questions/3934044/{$row['p']}'$selected>{$row['p']}</option>"; }\[/code\]When i use query \[code\]SELECT DISTINCT p\[/code\], \[code\]$selected\[/code\] isn't working, however if i use \[code\]SELECT p\[/code\]. Its working, any idea why?