title: Display Label on a Line Chart in ireport
body: <p>I am new to ireport and I want to have a line Chart.
  I want to know is there anyway to add a label on the chart axis?
  I think that I should set the Value Axis Label Expression, but how can I set it to  a string like: "hours"?</p>
  
  <p>Also, is there any way to show some numbers on the points in the line chart?</p>