Untitled

<HTML>
<head>
    <style>
    input[type=button]{
    margin: 1px 1px 1px 1px;
    height: 50px;
    width: 50px;
    border: 2px solid brown;
    font-size: 30px;
    }
    input[type=text]{
    height: 50px;
    width: 225px;
    border: 2px solid black;
    margin-bottom: 10px;
    font-size: 30px;
    font-color: black;
    }
</style>
    <script type="text/javascript">
    function displynum(n1) {
    calcform.txt1.value=calcform.txt1.value+n1;
    }
</script>
</head>
<body>

    <div style=" width: 220px; padding:5px; height:43%; align2 ;  background-color: lightblue";>

        <form name=calcform>

    <input type=text placeholder="0" name=txt1 style="text-align:right; width: 220px">
    <br>
    <input type=button name=btn9 value=9 onclick="displynum(btn9.value)">
    <input type=button name=btn8 value=8 onclick="displynum(btn8.value)">
    <input type=button name=btn7 value=7 onclick="displynum(btn7.value)">
    <input type=button name=addbtn value=+ onclick="displynum(addbtn.value)">
    <br>
    <input type=button name=btn6 value=6 onclick="displynum(btn6.value)">
    <input type=button name=btn5 value=5 onclick="displynum(btn5.value)">
    <input type=button name=btn4 value=4 onclick="displynum(btn4.value)">
    <input type=button name=subbtn value=- onclick="displynum(subbtn.value)">
    <br>
    <input type=button name=btn3 value=3 onclick="displynum(btn3.value)">
    <input type=button name=btn2 value=2 onclick="displynum(btn2.value)">
    <input type=button name=btn1 value=1 onclick="displynum(btn1.value)">
    <input type=button name=btnmul value=* onclick="displynum(btnmul.value)">
    <br>
    <input type=button name=btn0 value=0 onclick="displynum(btn0.value)">
    <input type=button name=potbtn value=. onclick="displynum(potbtn.value)">
    <input type=button name=eqlbtn value="=" onclick="txt1.value=eval(txt1.value)">
    <input type=button name=divbtn value=/ onclick="displynum(divbtn.value)">
    </form>
    </div>
</body>
</html>