<!DOCTYPE html>
<html>
    <head>
		<meta charset= "utf-8">
		<script src= "d3.js"></script>
        <script>
            function makeSVG() {
                var l = [30, 60];
                cs = d3.select("#fig").selectAll("circle").data(l)
                cs.exit().remove();
                cs.attr("r", d=>d);
            }
        </script>
    </head>
    <body onload="makeSVG()">

        <svg id="fig" width="500" height="500" style="background: lightgrey">
            <circle cx="100" cy="250" r="10" />
            <circle cx="200" cy="250" r="10" />
            <circle cx="300" cy="250" r="10" />
        <svg>

    </body>
</html>

<!DOCTYPE html>
<html>
    <head>
		<meta charset= "utf-8">
		<script src= "d3.js"></script>
        <script>
            function makeSVG() {
                var l = [30, 60];
                cs = d3.select("#fig").selectAll("circle").data(l);
                cs.exit().remove();
                cs.attr("r", d=>d);
            }
        </script>
    </head>
    <body onload="makeSVG()">

        <svg id="fig" width="500" height="500" style="background: lightgrey">
            <circle cx="100" cy="250" r="10" />
            <circle cx="200" cy="250" r="10" />
            <circle cx="300" cy="250" r="10" />
        <svg>

    </body>
</html>

Fix a bug (missing semicolon).
Fix a bug (missing semicolon).
