Calculator Code

<!DOCTYPE html>
    <html>
        <head>

            <title>Test Page</title>

        </head>
        <body>

            <form name="calculator">

                <input type="button" value="1" onClick="document.calculator.ans.value+='1'">
                <input type="button" value="2" onClick="document.calculator.ans.value+='2'">
                <input type="button" value="3" onClick="document.calculator.ans.value+='3'">
                <input type="button" value="4" onClick="document.calculator.ans.value+='4'">
                <input type="button" value="5" onClick="document.calculator.ans.value+='5'">
                <input type="button" value="6" onClick="document.calculator.ans.value+='6'">
                <input type="button" value="7" onClick="document.calculator.ans.value+='7'">
                <input type="button" value="8" onClick="document.calculator.ans.value+='8'">
                <input type="button" value="9" onClick="document.calculator.ans.value+='9'">
                <input type="button" value="0" onClick="document.calculator.ans.value+='0'">
                <input type="button" value="+" onClick="document.calculator.ans.value+='+'">
                <input type="button" value="-" onClick="document.calculator.ans.value+='-'">
                <input type="button" value="/" onClick="document.calculator.ans.value+='/'">
                <input type="button" value="*" onClick="document.calculator.ans.value+='*'">
                <input type="button" value="=" onClick="document.calculator.ans.value=eval(document.calculator.ans.value)">
                <input type="reset" value="Reset">

                <br>Solution is <input type="textfield" name="ans" value="">

            </form>

        </body>

    </html>