Run this script using the default value provided when you "submit" it:

<title>Test</title>
<center>
<h1>Test</h1>
<?
if ($posted):
  $d2 = 1999;
  $d1 = intval($d1*100);
  if ($d1 == $d2):
    echo "They are equal";
  else:
    echo "$d1 ", gettype($d1), " is not equal to $d2 ", gettype($d2);
  endif;
else:
  $d1 = 1999;
  $d1 = sprintf("%.2f",$d1/100);
  echo "<form method=post action=test.html>";
  echo "<input type=input name=d1 value=$d1>";
  $posted = 1;
  echo "<input type=hidden name=posted value=$posted>";
  echo "<input type=submit value=submit></form>";
endif;
?>