public variable not accessible, why??

[LiteUponLite]

i've a public variable declared inside the class (ArrayList arr) and when i try to access it within the methods of the class (like Parser) it gives me an error, why?? like if i've declared it public i shud be able to access it, i've done this before too. Also how wud i access this variable in any other class, do i need to create accessor methods in this class for that. Below is the structure of the class:

using System;
using System.Collections;
using System.Text.RegularExpressions;


namespace HL7Convert
{

	
	class HL7Convert
                {

                 public ArrayList arr = new ArrayList();
                 public static String Parser (String fileNum, String fileName)
                }
}