Untitled

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>project4</title>
<script type="text/javascript" src="jquery-2.1.3.min.js"></script>
    <style>
        .div-parent {margin: auto; margin-top: 1%}
        .div-1{width: 48%;height: 300px;margin-top: 1%; margin-left: 1%; float: left; border: 1px solid transparent}
        .div-2{width: 48%; height:300px; margin-top: 1%; margin-left: 1%; float: left; border: 1px solid transparent}
        .div-3{width: 80%; height:200px; margin-top: 1%;border: 1px solid transparent;float: left;margin-left: 10%}
        #div-input{margin-top:20%; float: left; margin-left: 12%;width: 80%}
        #div-button{margin-top: 21%; float: left;margin-left: 10%;width: 12%}
        .input{
            width: 100%;height: 40px;
            border-radius: 5px;border: 1px solid #c2c2c2;
            font-size: 18px; padding-left: 12px;
        }
        .button{
            width: 100%;height:25px;
            border-radius: 5px; border: 1px solid #c2c2c2;
            background-color:lightslategrey; color: lightsteelblue;
            font-size: 14px; font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
            cursor: pointer
        }
        #text{text-align: center;padding-top: 6%}
    </style>
    <script>
        var a, b, c, d, e;
            $(document).ready( function(){
            a=$('.input');
            b=$('.button');
            c=$('#form');
            d= a.val();
            e=$('#text');
            b.click(function(){
                if (d<0){d=d*(-1)}
                if(d<10){
                    if(d==2||d==3||d==5||d==7){e.text('this is a prime number.');
                    }
                    else {e.text('this is not a prime number.');
                    }
                }
                else{e.text('the number is too big.');
                }
            });

        });


    </script>


</head>
<body>
<div class="div-parent" >
<div class="div-1" >
    <div id="div-input">
    <form id="form"> <input class="input" type="number" name="text" placeholder="input a number"
                  onfocus="this.placeholder='' " onblur="this.placeholder='input a number' "></form>
     </div>
</div>
<div class="div-2"  >
   <div id="div-button"> <button class="button" > Submit </button>
       </div>
</div>
<div class="div-3"> <h3 id="text"> hello! how was life ? are you well ?  </h3>
</div>
</div>
</body>
</html>