d3.lineChart = function() {
  var width = 400,
      height = 300,
      xExtent, yExtent,
      x, y,
      xScale = d3.scale.linear(), 
      yScale = d3.scale.linear(),
      path = d3.svg.line();
  
  function chart(selection, lineClass, data) {
    xScale
      .domain(xExtent || d3.extent(data, x))
      .range([0, width]);
    
    yScale
      .domain(yExtent || d3.extent(data, y))
      .range([height, 0]);
      
    path
      .x(function(d) { return xScale(x(d)); })
      .y(function(d) { return yScale(y(d)); });
    
    var lineSelectorString = "." + (lineClass.replace(" ", "."));
    
    var lines = selection.selectAll(lineSelectorString).data([data]);
    
    lines.enter().append("path")
      .attr("class", lineClass);
    
    lines
      .transition().duration(333)
        .attr("d", path);
      
    lines.exit().remove();
  }
  
  chart.width = function(_) {
    if (!arguments.length) return width;
    width = _;
    return chart;
  };
  
  chart.height = function(_) {
    if (!arguments.length) return height;
    height = _;
    return chart;
  };
  
  chart.x = function(_) {
    if (!arguments.length) return x;
    x = _;
    return chart;
  };
  
  chart.y = function(_) {
    if (!arguments.length) return y;
    y = _;
    return chart;
  };
  
  chart.xExtent = function(_) {
    if (!arguments.length) return xExtent;
    xExtent = _;
    return chart;
  };
  
  chart.yExtent = function(_) {
    if (!arguments.length) return yExtent;
    yExtent = _;
    return chart;
  };
  
  // Getter functions
  chart.xAxis = function() { return d3.svg.axis().scale(xScale).orient("bottom"); };
  chart.yAxis = function() { return d3.svg.axis().scale(yScale).orient("left"); };
  chart.xScale = function() { return xScale; };
  chart.yScale = function() { return yScale; };
  
  return chart;
}