d3 Line graph dual y-axis

Hi,

 I am trying to create the dual y axis line chart from the d3 code : http://bl.ocks.org/d3noob/e34791a32a54e015f57d

Changed the D3 code as per the D3JSVisuals instruction.  I notice that the path is not getting constructed. The lines always start from one point and not join from the previous point. 

I have put in the modified code as per custom visual instruction and the screenshot. Require help in resolving the same.

Code:

var margin = {top: 30, right: 40, bottom: 30, left: 50},
width = pbi.width - margin.left - margin.right,
height = pbi.height - margin.top - margin.bottom;

var parseDate = d3.time.format("%d-%b-%y").parse;

var x = d3.time.scale().range([0, width]);
var y0 = d3.scale.linear().range([height, 0]);
var y1 = d3.scale.linear().range([height, 0]);

var xAxis = d3.svg.axis().scale(x)
.orient("bottom").ticks(5);

var yAxisLeft = d3.svg.axis().scale(y0)
.orient("left").ticks(5);

var yAxisRight = d3.svg.axis().scale(y1)
.orient("right").ticks(5);

/*var valueline = d3.svg.line()
.x(function(d) { return d.date; })
.y(function(d) { return d.close; })
.interpolate("linear");
*/
var valueline = d3.svg.line()
.x(function(d) { return x(d.date); })
.y(function(d) { return y0(d.close); })
.interpolate("cardinal");

var valueline2 = d3.svg.line()
.x(function(d) { return x(d.date); })
.y(function(d) { return y1(d.open); });

var svgCont = d3.select("#chart")
.append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", 
"translate(" + margin.left + "," + margin.top + ")");

// Get the data
pbi.dsv(function(data) {

data.forEach(function(d) {
d.date = parseDate(d.date);
d.close = +d.close;
d.open = +d.open;
});

// Scale the range of the data
x.domain(d3.extent(data, function(d) { return d.date; }));
y0.domain([0, d3.max(data, function(d) {
return Math.max(d.close); })]); 
y1.domain([0, d3.max(data, function(d) { 
return Math.max(d.open); })]);

svgCont.append("path") // Add the valueline path.
.attr("class","line")
.attr("d", valueline(data));

/*svg.append("path") // Add the valueline2 path.
.style("stroke", "red")
.attr("d", valueline2(data));*/

svgCont.append("g") // Add the X Axis
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);

svgCont.append("g")
.attr("class", "y axis")
.style("fill", "steelblue")
.call(yAxisLeft);

svgCont.append("g") 
.attr("class", "y axis") 
.attr("transform", "translate(" + width + " ,0)") 
.style("fill", "red") 
.call(yAxisRight);

});