// action to take on mouse click
function click() {
d3.select(this).select("text").transition()
.duration(750)
.attr("x", 22)
.style("fill", "steelblue")
.style("stroke", "lightsteelblue")
.style("stroke-width", ".5px")
.style("font", "20px sans-serif");
d3.select(this).select("circle").transition()
.duration(750)
.attr("r", 16)
.style("fill", "lightsteelblue");