in my assignment I trying to create a popup box but someting wrong with my code. it supposed to popup when called and close as it have a close button but the button is not working

can something tell me what did i do wrong.

here is my code: is there somethings that some else can i and I cant

<?php
    /*session_start();
    if(!isset($_SESSION['view']))
    {
        header("location:../xhtml/login.html");
    }*/

?>

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
    <head>
        <title> Caribbean Nature Seekers Institute Trinidad and Tobago Chapter</title>
        <link rel="stylesheet" type="text/css" href="../css/stylesheet.css" />
    </head>
    <body>
        <div id="container">

            <div id="header">
                <div  id="banner">
                    <img src="../images/header.jpg" alt="header" />
                </div>
            </div>
            <div id="navbar">
                <ul>

                    <li><a  href="../index.html" id="tlinks" class="toplinks">Homepage</a></li>
                    <li><a  href="featureNaturalWonders.html" id="thold" class="toplinks">Feature Natural Wonders</a></li>
                    <li><a  href="contact.html" id="linkhold" class="toplinks" >Contact Us</a></li>
                    <li><a  href="register_user.html" id="phold" class="toplinks"> Sign Up</a></li>
                    <li><a  href="login.html" id="loglinks"class="toplinks"> Login</a></li>
                    <li><a  href="aboutus.html" id="panlinks" class="toplinks"> About Us</a></li>

                </ul>   
                    <form method="post" id="search"   action="" >                       
                        <input type="text" name="search" value=""/>
                        <input type="submit" value="Search"/>                                               
                    </form>             

            </div>  

            <br/>
            <br/>
            <br/>

<html lang="en" dir="ltr">  
    <head>
        <meta charset="utf-8">
        <link rel="stylesheet" href="../css/stylesheet.css"/>

    </head>
    <body>
        <div class="show_box">
            <a class="btn">show Box</a>
            <div id="box">
                <span class="ion-checkmark-round"></span>

                <h1>"Hi Welcome!!!!!! Luana Taylor, you are now are member of Caribbean Nature Seekers InstituteTT ('CNSITT')");</h1>

                <a class="close">Close</a>

            </div>

            <script  type="text/javascript">
             var c=0'

             function pop()
             {
                 if(c == 0)
                 {
                     document.getElementById("box").style.display = "block";
                     c ==1;

                 }
                 else
                 {
                     document.getElementById("box").style.display = "none";
                     c ==1;
                 }
             }
        </div>
    </body>
</html>

        <div id="contentArea">

            <div id="footerbox">

                    <div id="footerholder">
                        <div id="">

                            <a href="../index.php">Homepage</a>
                            <a href="popupbox.php">Popup box </a>
                            <a href="featureNationalWonders.php">Feature National Wonders</a>           

                        </div>

                    </div>
            </div>
            <div id="footerFix"></div>              
                <div id="footerbox">
                    <div id="footer" >
                        <div id="footerholder" >
                            <ul>
                                <li><a  href="../index.html"  class="toplinks">Homepage</a></li>
                                <li><a  href="xhtml/featureNationalWonders.html"  class="toplinks">Feature National Wonders</a></li>
                                <li><a  href="xhtml/contact.html"  class="toplinks" >Contact Us</a></li>
                                <li><a  href="xhtml/register_user.html"  class="toplinks">Sign Up</a></li>
                                <li><a  href="xhml/login.html" class="toplinks">Login</a></li>
                                <li><a  href="xhtml/aboutus.html"  class="toplinks">About Us</a></li>
                            </ul>
                        </div>
                    </div>                      
                </div>
        </div>

</html>

I'm having a hard time understanding your code. You seem to have nested <html> tags, which is not valid HTML markup. You close one HTML tag on line 82 but then you have a <div> on line 84, so I'm confused what you're trying to achieve or what you want this to look like.

Also, in Javascript, var c = 0; sets the value of the variable c to 0. If you want to do comparisons, you can do something like if (c == 0). However, it looks like you're using double equals on lines 71 and 77, and I'm not quite sure what you're trying to do there either. You seem to be saying that whether or not c is currently 0, set it to 1 (assuming you meant for it to be c = 1;).