PHP-Isset function is not working
<p>I am new to PHP. My isset function is not working .It does not not show  error .It always insert the table. I have given my code. Kindly advice what i done wrong on this</p>

<pre><code>&lt;?php
if(isset($_POST['submit'])) {
    $a= $_POST['companyname'];
    $b= $_POST['ballpark_url'];
    $c= $_POST['username'];
    $d= $_POST['email'];
    $e= $_POST['login1'];
    $f= $_POST['pass'];
    $error = false;
    if(validname($a) ==false) {
        echo $nameerror = "enter the valid name";
    }
    if(validemail($d) ==false) {
        echo $nameerror = "enter the valid email";
    }
    if(isset($_POST['companyname'])) {
        if($error==false) {
            $query= "INSERT INTO user VALUES ('$a','$b','$c','$d','$e','$f','');";
            if(!mysql_query($query)) {
                die ('error:'.mysql_error());
            }
            mysql_close($conn);  
        }
        include("templats/header_1.html");
        include("templats/content.html");
        include("templats/footer.html");
    }
?&gt;
</code></pre>

<p>kindly rectify the issue in my code and send back to me...</p>
