function showDetail(d) {
    // change outline to indicate hover state.
    d3.select(this).attr('stroke', 'black');

    var content = '<span class="name">Title: </span><span class="value">' +
                  d.name +
                  '</span><br/>' +
                  '<span class="name">Amount: </span><span class="value">$' +
                  addCommas(d.value) +
                  '</span><br/>' +
                  '<span class="name">Year: </span><span class="value">' +
                  d.year +
                  '</span>';

    tooltip.showTooltip(content, d3.event);
  }
/*
   * Function called on mouseover to display the
   * details of a bubble in the tooltip.
   */
Function called on mouseover to display the
details of a bubble in the tooltip.
Function called on mouseover to display the details of a bubble in the tooltip .
function showDetail(d) {
    d3.select(this).attr('stroke', 'black');
    var content = '<span class="name">Title: </span><span class="value">' +
                  d.name +
                  '</span><br/>' +
                  '<span class="name">Amount: </span><span class="value">$' +
                  addCommas(d.value) +
                  '</span><br/>' +
                  '<span class="name">Year: </span><span class="value">' +
                  d.year +
                  '</span>';
    tooltip.showTooltip(content, d3.event);
  }
function showDetail ( d ) { d3 . select ( this ) . attr ( 'stroke' , 'black' ) ; var content = '<span class="name">Title: </span><span class="value">' + d . name + '</span><br/>' + '<span class="name">Amount: </span><span class="value">$' + addCommas ( d . value ) + '</span><br/>' + '<span class="name">Year: </span><span class="value">' + d . year + '</span>' ; tooltip . showTooltip ( content , d3 . event ) ; }
Function called on mouseover to display the
 details of a bubble in the tooltip.
Function called on mouseover to display the details of a bubble in the tooltip .
// change outline to indicate hover state.