D3 id selection example by NelsonMinar

index.html

<!DOCTYPE html>
<html><head><script type="text/javascript" src="https://github.com/mbostock/d3/raw/master/d3.js"></script></head><body>

<script lang="text/javascript">
window.onload = function() {
    // Create a red rectangle
    d3.select("body").append("svg:svg")
        .attr("width", "100").attr("height", "100")
      .append("svg:rect")
        .attr("id", "myrectangle")
        .style("fill", "red")
        .attr("width", "100").attr("height", "100");

    // Now turn the rectangle blue, via an ID selector
    setTimeout(function() {
      d3.selectAll("#myrectangle").style("fill", "blue"); 
    }, 2000);
}
</script></body></html>