title: get value of selected index of combo box in javascript
body: <p>i am trying to get the value of the selected index in my javascript </p>
  
  <p>here i am defining my list box</p>
  
  <pre><code>&lt;select name="combo" id="combo"  OnBlur="retrieveData(this.form)" &gt;&lt;/select&gt;
  </code></pre>
  
  <p>here i am trying to get the value (inside the form) </p>
  
  <pre><code>    alert(form.combo.value); // NOT working
      alert(form.combo.selectedIndex)  // working
      alert(form.combo.selectedIndex.value)  // NOT working
  </code></pre>
  
  <p>but its showing "undefined"</p>