There are couple of things
1. You need to comment out $_SESSION['count'] = $count; because $count variable is no way to be found
2. move the session_start(); to the top
3. wrap the code with if (isset($_POST['validate'])) { so that the session variable will not be overwritten on page load
4. maybe you didn't post complete code, there is no submit button on the form.
Here how the code should look like.
<?php
session_start();
if (isset($_POST['validate'])) {
$mo = filter_input(INPUT_POST, "mo");
$dy = filter_input(INPUT_POST, "dy");
$yr = filter_input(INPUT_POST, "yr");
$hr = filter_input(INPUT_POST, "hr");
$mn = filter_input(INPUT_POST, "mn");
$sc = filter_input(INPUT_POST, "sc");
$_SESSION['mo'] = $mo;
$_SESSION['dy'] = $dy;
$_SESSION['yr'] = $yr;
$_SESSION['hr'] = $hr;
$_SESSION['mn'] = $mn;
$_SESSION['sc'] = $sc;
session_write_close();
}
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html lang="EN" dir="ltr" xmin="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/xml; charset=utf-8" />
<title>Title.php</title>
...
</head>
<body>
<form id="myform" method="Post" action="">
<center><table><tr>
<td align="center"><input type="text" name="mo" value="<?php echo $_SESSION['mo']; ?>" size="4"/></td>
<td align="center"><input type="text" name="dy" value="<?php echo $_SESSION['dy']; ?>" size="4"/></td>
<td align="center"><input type="text" name="yr" value="<?php echo $_SESSION['yr']; ?>" size="4"/></td>
<td align="center"><input type="text" name="hr" value="<?php echo $_SESSION['hr']; ?>" size="4"/></td>
<td align="center"><input type="text" name="mn" value="<?php echo $_SESSION['mn']; ?>" size="4"/></td>
<td align="center"><input type="text" name="sc" value="<?php echo $_SESSION['sc']; ?>" size="4"/></td>
</tr</table></center>
</form>
<input type='submit' name="validate" id="validate" value='Submit' />
</body>
</html>