C#

Hi,

I want to validate the xml file against certain set of rules in database.I have done most of the this but got stuck in below part. Any pointers will be appreciated.
Following is the sample xml file.
<pre lang="xml">
<BACKGROUND>
        <QUES_NUMBER>1</QUES_NUMBER>
        <QUES_RESPONSE>Y</QUES_RESPONSE>
      </BACKGROUND>
      <BACKGROUND>
        <QUES_NUMBER>2</QUES_NUMBER>
        <QUES_RESPONSE>Y</QUES_RESPONSE>
      </BACKGROUND>
      <BACKGROUND>
        <QUES_NUMBER>3</QUES_NUMBER>
        <QUES_RESPONSE>Y</QUES_RESPONSE>
      </BACKGROUND>
      <BACKGROUND>
        <QUES_NUMBER>4</QUES_NUMBER>
        <QUES_RESPONSE>N</QUES_RESPONSE>
      </BACKGROUND>
      <BACKGROUND>
        <QUES_NUMBER>5</QUES_NUMBER>
        <QUES_RESPONSE>Y</QUES_RESPONSE>
      </BACKGROUND>
      <BACKGROUND>
        <QUES_NUMBER>1A</QUES_NUMBER>
        <QUES_RESPONSE>Y</QUES_RESPONSE>
      </BACKGROUND>

public static bool PROCESSRULE_RANGE(string expValue, ArrayList xmlValColl, out int valIndex)//, out Array avlValue
       {

               string currentValue = string.Empty;
               valIndex = -1;
               string[] expValArr = expValue.Split(new char[] { ' ', ',' }, StringSplitOptions.RemoveEmptyEntries);

               var intersect = expValArr.Intersect(xmlValColl.ToArray());

               if (intersect.Count() > 0)
               {
                   valIndex = xmlValColl.IndexOf(intersect.First());
                   return true;
               }

       }

private void button1_Click(object sender, EventArgs e)
       {
           backgroundWorker2.RunWorkerAsync();
       }
       public void additem(int i)
       {
           listBox1.Items.Add(i);
       }

       private void backgroundWorker2_DoWork(object sender, DoWorkEventArgs e)
       {
           for (int i = 0; i < 10; i++)
           {
               additem(i);
               Thread.Sleep(500);
           }

       }

delegate void SetUpdatesCallback();

public void ButtonUpdatesPerformClick()
{
    if (this.buttonUpdates.InvokeRequired)
    {
        SetUpdatesCallback button = new SetUpdatesCallback(this.ButtonUpdatesPerformClick);
        this.Invoke(button, new object[] { });
    }
    else
    {
         this.buttonUpdates.PerformClick();
    }
}
private void buttonUpdates_Click(object sender, EventArgs e)
{
    this.NonButtonUpdates();
}
private void NonButtonUpdates()
{
    this.GoToWebsiteGetData();
}

// CA.cs
public static class A
{
public static void Show()
{
string myFile = .... // here should read where the code is i.e c:\myproject\CA.cs
Console.WriteLine(myFile);
}
}