if (m > lineCount)

					lineCount = m;

			}

		}

		var edge_pad = this.dot_radius + 2;

		var box_size = Math.min(18, Math.floor((canvasWidth - edge_pad*2)/(lineCount)));

		var base_x = canvasWidth - edge_pad;

		for (var i=0; i < data.length; ++i) {

			var row = document.getElementById("chg_"+idx);

				continue;

			var	next = document.getElementById("chg_"+(idx+1));

			var extra = 0;

			cur = data[i];

			node = cur[0];

			in_l = cur[1];

			closing = cur[2];

			var rowY = row.offsetTop + row.offsetHeight/2 - rela.offsetTop;

			var nextY = (next == null) ? rowY + row.offsetHeight/2 : next.offsetTop + next.offsetHeight/2 - rela.offsetTop;

			for (var j in in_l) {

				start = line[0];

				end = line[1];

				color = line[2];

				x = base_x - box_size * start;

				// figure out if this is a dead-end;

				// we want to fade away this line

				var dead_end = true;

				if (next != null) {

					nextdata = data[i+1];

					next_l = nextdata[1];

					for (var k=0; k < next_l.length; ++k) {

						if (next_l[k][0] == end) {

							dead_end = false;

							break;

						}

					}

					if (nextdata[0][0] == end) // this is a root - not a dead end

						dead_end = false;

				}

				if (dead_end) {

					var gradient = this.ctx.createLinearGradient(x,rowY,x,nextY);