How to read XML data in Javascript - Help is Needed**

Question

Hi All,
I have a following XML document
<root>
  <fault>
  <text selected_value="Pending fault">Pending Fault found on</text> 
  <text selected_value="Already repaired">Repaired Fault on</text>
  // I may add two or more text nodes in future
  </fault>
  <genere>
  <text>Aircraft</text>
  <text>Component</text>
  <text>Subsystem</text>
  </genere>
</root>
In the aspx file I have a autocomplete textbox(tbauto) which will display the contenets of the 'text' node of 'fault' element. Below this autocomplete textbox I have a normal textbox(tbname).Till this I have no problem.
Now what I want is
if I select a 'Pending Fault found on' option from the autocomplete popup then, I want the 'select_value' attribute's value (i.e.,'Pending fault' ) of the first text node to be displayed on the textbox(tbname). if I select a 'Repaired Fault on' option from the autocomplete popup then, I want the 'select_value' attribute's value (i.e.,'Already repaired' ) of the second text node to be displayed on the textbox(tbname), and so on.
 I have a following javascript function (in this function I want to know how to get the data from XML and use it instead of hardcoding )
function SetFaultAction(popupValue) { 
// here the popupValue is the value selected in the textbox(according to my XML template its either 'Pending Fault found on' or 'Repaired Fault on')
  var pendingFault =  "Pending fault";
  var repairedfault = "Already repaired";
  if (popupValue.search(/Pending/i) > -1) {
  document.getElementById('tbname').value = pendingFault;
  }
  else if (popupValue.search(/repaired/i)> -1){
  document.getElementById('tbname').value = repairedfault;
  }

the above javascript works fine. (But if I add two more text nodes under the fault element then the above javascript function will not work for those two newly added nodes). But what I want is, the values should be read from XML instead of hardcoding like popupValue.search(/Pending/i) > -1) and var pendingFault =  "Pending fault";
Thanks,
Sachi