Page Reload

I am trying a site like http://quizpage.com/..i have all the questions and options in the database and displaying all the questions with choices using a select query.Also i have an additional field named "correct answer" and i check whether the selected option is equal to the correct answer..My problem now is after clicking any of the option,it displays "right" or "wrong" and is automatically moving to the next question which should not happen.only after clicking the continue button it should move to the next question and if the answer is right or wrong that particular option should be highlighted in green or red respectively..what i should do for this??pls guide me.
my coding is as follows:

<?


include "includes/connection.php";


//if(isset($_POST['continue'])){


$result=mysql_query("select mathID,Question, option1, option2, option3, option4, option5, correctanswer from math_table ORDER BY RAND() LIMIT 1");


$resultset=mysql_fetch_array($result);


//}


$option=$_REQUEST['option'];


//$id=$_REQUEST['id'];


$result1=mysql_query("select correctanswer from math_table where mathID='$_GET[id]'");


$resultset1=mysql_fetch_array($result1);


echo $option;


echo $resultset1['correctanswer'];


$divcolor="blue";


if($option==$resultset1['correctanswer'])


{


    $divcolor="green";


}


else


{


    $divcolor="red";


}


?>


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">


<html xmlns="http://www.w3.org/1999/xhtml">


<head>


<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />


<title>Untitled Document</title>


<script type="application/javascript">


function showcont(){


document.getElementById('continue').style.display='block';


}


</script>


</head>


<body>


<form>


<? if($divcolor=="green") { ?>


<div style="border:solid; border-color:#66CC66; width:50%; margin-left:250px; margin-top:150px;border-width:25px;"> 


<? } ?>


<? if($divcolor=="red") { ?>


<div style="border:solid; border-color:#FF0000; width:50%; margin-left:250px; margin-top:150px;border-width:25px;"> 


<? } ?>


<? if($divcolor=="blue") { ?>


<div style="border:solid; border-color:#0033FF; width:50%; margin-left:250px; margin-top:150px;border-width:25px;"> 


<? } ?>


<div>


<? $count=1; ?>


Question <? echo $count; ?></div>


<ol><b><? echo $resultset['Question']; ?></b>


<? if($resultset['option1']!='') { ?>


<div>


<li><a href="maths1.php?option=<?= $resultset['option1'];?>&id=<?= $resultset['mathID']; ?>" onclick="showcont();"><? echo $resultset['option1']; ?></a></li>


<li><a href="maths1.php?option=<?= $resultset['option2'];?>&id=<?= $resultset['mathID']; ?>" onclick="showcont();"><? echo $resultset['option2']; ?></a></li>


<li><a href="maths1.php?option=<?= $resultset['option3'];?>&id=<?= $resultset['mathID']; ?>" onclick="showcont();"><? echo $resultset['option3']; ?></a></li>


<? if($resultset['option4']!='') {?>


<li><a href="maths1.php?option=<?= $resultset['option4'];?>&id=<?= $resultset['mathID']; ?>" onclick="showcont();"><? echo $resultset['option4']; ?></a></li>


<? } ?>


<? if($resultset['option5']!='') {?>


<li><a href="maths1.php?option=<?= $resultset['option5'];?>&id=<?= $resultset['mathID']; ?>" onclick="showcont();"><? echo $resultset['option5']; ?></a></li>


<? }?>


</div>


<? } 


else{ ?>


<input type="text" name="answer" id="answer"/>


<?


}


?>


</ol>


<br />


</div><br />


<div align="center">


<? if($divcolor=="red" || $divcolor=="green") { ?>


<input type="submit" name="continue" value="Continue" id="continue" style="display:none;"/>


<? } ?>


  <input type="submit" name="quit" value="Quit" id="quit"/></div>


  </form>




</body>