HTML 선택이 올바르게 작동하지 않음

HTML 선택 상자를 사용하는 계산기를 코딩하고 있습니다. 그러나 선택 값이 내 PHP 코드로 제대로 게시되지 않습니다. 누구든지 가능한 통찰력을 제공 할 수 있습니까? 나는 무엇이 잘못되었는지 전혀 모른다. 여기에서 계산기를 사용해 볼 수 있습니다. http://macrorevolution.com/calculators/1-rep-max/

제출을 누르면 값이 지워지고 결과가 제공되지 않습니다. http://macrorevolution.com/calculators/total-daily-energy-expenditure/ 와 같은 다른 계산기 에서는 입력 한 값이 제출 후에도 유지됩니다.

PHP 코드 :

<?php
$repsv = "";
$weightliftv = "";
$answer = "";
if(isset($_POST['weightliftv'])) {
    $repsv = $_POST['repsv'];
    $weightliftv = $_POST['weightliftv'];
    if ($repsv=='0');
    else if($repsv=='1v') $repsv=1;
    else if($repsv=='2v') $repsv=1.0285949393;
    else if($repsv=='3v') $repsv=1.0588733587;
    else if($repsv=='4v') $repsv=1.0909884355;
    else if($repsv=='5v') $repsv=1.1251125112;
    else if($repsv=='6v') $repsv=1.1614401858;
    else if($repsv=='7v') $repsv=1.2001920307;
    else if($repsv=='8v') $repsv=1.2416190713;
    else if($repsv=='9v') $repsv=1.2860082305;
    else if($repsv=='10v') {$repsv=1.3333333333; echo "10";}
    else echo "error";
    $answer = $weightliftv * $repsv;
}
?>

다음은 같은 파일에있는 html 코드입니다.

<form method='post' action=''>
<table width='80%' style="margin: 0 auto;">


    <tr class="spaceUnder">
        <td>Weight Lifted:</td>
        <td><input type='text' name='agev' value="<?php echo $agev; ?>"/>lbs</td>
    </tr>
    <tr class="spaceUnder">
    <td>Reps Done</td>
    <td colspan="2">
        <select name="repsv">
  <option name='repsv' selected='selected' value=''>Select</option>
  <option name='repsv' value='1v'>1 Reps</option>
  <option name='repsv' value='2v'>2 Reps</option>
  <option name='repsv' value='3v'>3 Reps</option>
  <option name='repsv' value='4v'>4 Reps</option>
  <option name='repsv' value='5v'>5 Reps</option>
  <option name='repsv' value='6v'>6 Reps</option>
  <option name='repsv' value='7v'>7 Reps</option>
  <option name='repsv' value='8v'>8 Reps</option>
  <option name='repsv' value='9v'>9 Reps</option>
  <option name='repsv' value='10v'>10 Reps</option>
         </select>
        </td>
        </tr>

    <tr class="spaceUnder">
        <td colspan="2"><input type='submit' class="button highlight small" value='Calculate'/></td>
    </tr>
    <tr class="spaceUnder">
        <td colspan="2"><strong>Your one rep max is </strong><input type='text' style="width: 50px; font-weight:bold;" value='<?php echo round($answer,0); ?>' /><strong>lbs</strong>  </td>
    </tr>

</table>
</form>

필요한 경우 전체 코드는 다음과 같습니다.

<?php
/*
Template Name: 1repcalc
*/
?>



<?php get_header(); ?>



<?php $al_options = get_option('al_general_settings');?>



<!-- Title -->

<div class="box pt20">

    <!-- Title -->

    <div class="headertext">

        <?php the_title() ?>

        <?php $headline = get_post_meta($post->ID, "_headline", $single = false);?>

        <?php if(!empty($headline[0]) ):?>

            <span><?php echo $headline[0] ?></span>

        <?php endif?>

    </div>

    <div class="clearsmall"></div>



    <!-- Promo text -->

    <?php $promo = get_post_meta($post->ID, "_promo", $single = false);?>

    <?php if(!empty($promo[0]) ):?>

       <div class="calloutcontainer">

            <div class="container_12">

                <div class="grid_12">            

                    <?php echo do_shortcode($promo[0]);?>

                </div>

            </div>

        </div>    

    <?php endif?>

    <div class="container_12">

        <?php if ( have_posts() ) while ( have_posts() ) : the_post(); ?>

            <?php the_content(); ?>

        <?php endwhile; ?>

    </div>

</div>
<!-- ///////////////////////////////////////////////////////////////////////////////////////////-->
<?php
$repsv = "";
$weightliftv = "";
$answer = "";
if(isset($_POST['weightliftv'])) {
    $repsv = $_POST['repsv'];
    $weightliftv = $_POST['weightliftv'];
    if ($repsv=='0');
    else if($repsv=='1v') $repsv=1;
    else if($repsv=='2v') $repsv=1.0285949393;
    else if($repsv=='3v') $repsv=1.0588733587;
    else if($repsv=='4v') $repsv=1.0909884355;
    else if($repsv=='5v') $repsv=1.1251125112;
    else if($repsv=='6v') $repsv=1.1614401858;
    else if($repsv=='7v') $repsv=1.2001920307;
    else if($repsv=='8v') $repsv=1.2416190713;
    else if($repsv=='9v') $repsv=1.2860082305;
    else if($repsv=='10v') {$repsv=1.3333333333; echo "10";}
    else echo "error";
    $answer = $weightliftv * $repsv;
    echo $answer;
}
?>


<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" >
<title>One Rep Max Calculator</title>
<style>
  table {
    font-size:15px;
    font-family: 'PT Sans', sans-serif;
    background-color:#FFFFFF;
  }
tr.spaceUnder > td
{
  padding:0em 1em 1em 0em;

}
p.ss {
    font-size:30px; 
    text-align:center
}
input {
margin-right:5px;
margin-left:5px;
}

</style>
</head>
<body>
<div class="box pt20">
<p class="ss">MacroRevolution One Rep Max Calculator</p><br>
<table width='80%' style="margin: 0 auto;">
    <tr class="spaceUnder">
    <td colspan="4">

All weight training and resistance training programs are always based off of your 1 rep max. If you are uncertain of your 1 rep max you can use the 1 rep max calculator below to help get you pretty close to that number.
In many cases we find that the 1 rep max calculator is accurate within 5%. The closer you can get to completing 1 rep at maximum effort, the more accurate it will be!
    </td>
    </tr>
</table>

<form method='post' action=''>
<table width='80%' style="margin: 0 auto;">


    <tr class="spaceUnder">
        <td>Weight Lifted:</td>
        <td><input type='text' name='agev' value="<?php echo $agev; ?>"/>lbs</td>
    </tr>
    <tr class="spaceUnder">
    <td>Reps Done</td>
    <td colspan="2">
        <select name="repsv">
  <option name='repsv' selected='selected' value=''>Select</option>
  <option name='repsv' value='1v'>1 Reps</option>
  <option name='repsv' value='2v'>2 Reps</option>
  <option name='repsv' value='3v'>3 Reps</option>
  <option name='repsv' value='4v'>4 Reps</option>
  <option name='repsv' value='5v'>5 Reps</option>
  <option name='repsv' value='6v'>6 Reps</option>
  <option name='repsv' value='7v'>7 Reps</option>
  <option name='repsv' value='8v'>8 Reps</option>
  <option name='repsv' value='9v'>9 Reps</option>
  <option name='repsv' value='10v'>10 Reps</option>
         </select>
        </td>
        </tr>

    <tr class="spaceUnder">
        <td colspan="2"><input type='submit' class="button highlight small" value='Calculate'/></td>
    </tr>
    <tr class="spaceUnder">
        <td colspan="2"><strong>Your one rep max is </strong><input type='text' style="width: 50px; font-weight:bold;" value='<?php echo round($answer,0); ?>' /><strong>lbs</strong>  </td>
    </tr>

</table>
</form>


<table border='0' width='80%' style="margin: 0 auto;">
    <td colspan="4">

      <br>
If you want to calculate your formula....
 <br><br><br>
    </td>
</table>
</div>

</body>
</html>

<!-- ///////////////////////////////////////////////////////////////////////////////////////////-->


<?php get_footer(); ?>