Maybe try
echo $dyoon;
instead of
echo "$dyoon";
like Rangad suggested in his/her comment
Also set $dyoon before while loop
$dyoon = 0;
while($addrow11=mysql_fetch_row($result11)){
$dyoon=$dyoon + $addrow11["12"];
}
echo $dyoon;
1
solved Notice: Undefined variable total not working in php 5.4 [closed]