php palindrome

<!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=windows-1252" />
<title>Untitled Document</title>
</head>

<body>

<?php

//$people = array("h","e","l","l","o");
//$result = sizeof($people);
//for($i=0;$i<=$result;$i--)
//{echo($people);}
    if ($_REQUEST['btnsubmit'] !="")
    {
$txtword = $_REQUEST['txtword'];   
  $str= $txtword;
  $str1=" ";
 $ctr=0;
        //To find the String Length
        while($str[$ctr])
        {
        $ctr++;
        }
        $i=$ctr;
        echo $i;
        //Storing it reversely in second array
        for($j=0;$j<$ctr;$j++){
                $str1[$j] = $str[$i-1];
                $i--;
        }

        //Check For Palindrome
        if($str==$str1)
                $pal="The String is a palindrome";
        else
                $pal= "The String is Not a Palindrome";
       
        //Display values
        echo "The Given String is ".$str."<br/><br/> The Reversed String is ".$str1."<br/<br/>";
        echo "<br/>".$pal;
}
?>
<form action="" name="frm" method="post">
<table border="1">
    <tr>
        <td>
            Enter a text:
        </td>
        <td>
            <input type="text" name="txtword" value="" />
        </td>
    </tr>
    <tr>
        <td>
            <input type="submit" name="btnsubmit" value="SUBMIT" />
        </td>
    </tr>
</table>
</form>
</body>
</html>