title: Combining a string with the value of a variable to be the name of another variable in EL
body: <p>I want to do something like this:</p>
  
  <pre><code>&lt;display:table name="${summary${index}}"&gt;
  </code></pre>
  
  <p>But it does not work throws exception: "${summary${selChrm}}" contains invalid expression(s). 
  I would like the user to use a drop down list to choose a selection and put in the variable index. Then the table will display the corresponding list of javabean objects, ie. named summary01, summary02, etc. How can I do that? Thanks in advance.</p>
  
  <hr>
  
  <p><strong>Update</strong>: Thanks guys. The problem is with the nested EL. I tried to use</p>
  
  <pre><code>&lt;display:table name="summary${index}"&gt;
  </code></pre>
  
  <p>But nothing shows in the table since summary01 is the variable name. If I hard code the variable name, it will work:</p>
  
  <pre><code>&lt;display:table name="${summary01}"&gt;
  </code></pre>
  
  <p>Therefore, how can I do nested EL? If it is not possibly in JSTL, how can I achieve the behavior that user can use a dropdown list to determine what contents to be display in the table? Thanks again.</p>