This is what Mordecai was referring to... (I would also recommend you single-quote your array index name too) Keep in mind, this will only work if your path is correct.......
<?
mysql_select_db($dbname, $link);
$result=mysql_query("select * from user_detail where nickname = '$name'") ;
$number_of_array = mysql_num_rows($result);
while ($number_of_array = mysql_fetch_array($result)){
echo"<img src=\"./image/".$number_of_array['image_name']."\">";
}
?>