Page refresh cause change to next questio n with session variable - php

Question

I have problem in retrieving one question on one page for online examination system from database. Currently I am retrieving with session variable. But problem in that is if we refresh page then session variable is increment and question is change with next serial number. Currently I am increment retrieving session variable from other page. So my question is how to solve change of question problem while refreshing page? Below is my code. and remaining code is in image file.
include("database.php");
$query="select * from ctip_question";
if($submit=='Next Question' && isset($ans))
{
mysql_data_seek($rs,$_SESSION[qn]);
$row= mysql_fetch_row($rs);
$question = $_SESSION[question];
$time = date('Y-m-d h:i:s');
mysql_query("insert into ctip_answer(test_id, q_no, qtype, answer,time) values ('1', '$_SESSION[qn]','$question','$ans','$time')") or die(mysql_error());
if($ans==$row[7])
{
$_SESSION[trueans]=$_SESSION[trueans]+1;
}
$_SESSION[qn]=$_SESSION[qn]+1;
$initialize_qn_no++;
}
else if($submit=='Get Result' && isset($ans))
{
mysql_data_seek($rs,$_SESSION[qn]);
$row= mysql_fetch_row($rs);
$time = date('Y-m-d h:i:s');
$question = $_SESSION[question];
mysql_query("insert into ctip_answer(test_id, q_no, qtype, answer,time) values ('1', '$_SESSION[qn]','$question','$ans','$time')") or die(mysql_error());
if($ans==$row[7])
{
$_SESSION[trueans]=$_SESSION[trueans]+1;
}
echo "<h1 class=head1> Result</h1>";
$_SESSION[qn]=$_SESSION[qn]+1;
echo "<Table align=center><tr class=tot><td>Total Question<td> $_SESSION[qn]";
echo "<tr class=tans><td>True Answer<td>".$_SESSION[trueans];
$w=$_SESSION[qn]-$_SESSION[trueans];
echo "<tr class=fans><td>Wrong Answer<td> ". $w;
echo "</table>";
mysql_query("insert into mst_result(login,test_id,test_date,score) values('$login',$tid,'".date("d/m/Y")."',$_SESSION[trueans])") or die(mysql_error());
echo "<h1 align=center><a href=review.php> Review Question</a> </h1>";
unset($_SESSION[qn]);
unset($_SESSION[sid]);
unset($_SESSION[tid]);
unset($_SESSION[trueans]);
exit;
}
$sql = "select * from ctip_test_question where test_id='$_SESSION[testid]' && sr_no=$_SESSION[qn]";
$result = mysql_query($sql);
while ($row1 = mysql_fetch_array($result)) {
{
$question = $row1['que_no'];
$_SESSION[question]=$question;
$rs=mysql_query("select * from ctip_question where que_id=$question",$cn) or die(mysql_error());
mysql_data_seek($rs,$_SESSION[qn]);
$row= mysql_fetch_row($rs);
echo "action=self_page";
$n=$_SESSION[qn]+1;
echo "here is my question";
echo "option1";
echo "option2";
echo "option3";
echo "option4";
if($_SESSION[qn]<20)
echo "next question";
else
echo "get result";
}
}