Shopping Cart Help

<!DOCTYPE html>

<html>

<head>

<script language="JavaScript">

    function show(shown, hidden) {
    document.getElementById(shown).style.display='block';
    document.getElementById(hidden).style.display='none';
    return false;
    }

    function AddtoCart() {
        console.log( 'hi');
        var x=document.getElementById('Items');
        var new_row = x.rows[1].cloneNode(true);
        var len = x.rows.length;
        new_row.cells[0].innerHTML = len;

        var inp1 = new_row.cells[1].getElementsByTagName('input')[0];
        inp1.id += len;
        inp1.value = '';
        var inp2 = new_row.cells[2].getElementsByTagName('input')[0];
        inp2.id += len;
        inp2.value = '';
        x.appendChild( new_row );
    }

</script>

</head>

<body>

  <div id="Main">

    <h1 align="center"> Welcome to our Online Shopping Site </h1> <hr>

    <p align="center"> View Cart    <a href="#" onclick="return show('Cart','Main');"> <img src="cart.jpg" height=50px width=45px> </img> </a> </p>

    <table id="Items" align="center" border="1" bgcolor="lightgreen">

        <tr>
            <td>Apple®</td>
            <td>iPad® with Wi-Fi + 3G 16GB</td>
            <td>$429.99</td>
            <td> <input type="image" src="cart.jpg" name="Cart" height="50px" width="45px" onclick="AddtoCart()"> </td>
        </tr>

        <tr>
            <td>Apple®</td>
            <td>iPad® mini Wi-Fi - 16GB - White and Silver</td>
            <td>$329.99</td>
            <td> <input type="image" src="cart.jpg" name="Cart" height="50px" width="45px" onclick="AddtoCart()"> </td>
        </tr>

        <tr>
            <td>HTC®</td>
            <td>HTC First® - Black;</td>
            <td>$99.99</td>
            <td> <input type="image" src="cart.jpg" name="Cart" height="50px" width="45px" onclick="AddtoCart()"> </td>
        </tr>

    </table>

  </div>

  <div id="Cart" style="display:none">

    <h1 align="center">Online Shopping Cart</h1>

    <table id="tablecart" align="center" border="1" bgcolor="lightgreen">

        <tr>
            <td>Total</td>
            <td id="Total"></td>
        </tr>
    </table>

   <p align="center"> <a href="#" onclick="return show('Main','Cart');">Return</a> </p>

  </div>


</body>

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