title: Excel Chart: How to add data points in one series from multiple sheets
body: <p>I have an excel document with multiple sheets. Each sheet contains data of separate test executions. Now I would like to create  to see the overall trends for all the executions. This requires that I use data from multiple sheets in one series. 
  An example to make this clear is that my y-axis would be constant but my y-axis of the chart would contain the following data: </p>
  
  <pre><code>1st entry: Sheet1 Cell B4 
  2nd entry: Sheet2 Cell B4
  3rd entry: Sheet3 Cell B4
  4th entry: Sheet4 Cell B4
  .....and so on.
  </code></pre>
  
  <p>Now, as i keep doing more executions, I would like to add data to the existing chart. </p>
  
  <p>COuld someone please help me with the following two points in excel: 
  1. How to add data to a single series from multiple sheets, as mentioned above by example?
  2. How do I keep adding data to the chart after each execution?</p>
  
  <p>Thanks, 
  Sunny</p>