Error when trying to parse csv file

I get a strange error when I try to take the data out of a csv file. I get : error CS1525: Unexpected symbol txt', expecting )‘, or `.’

Here is my script

    using UnityEngine;
using System.Collections;

public class Mindthecube : MonoBehaviour {

	// Use this for initialization
	void Start () { FileInfo theSourceFile = null;
TextReader reader = null;  // NOTE: TextReader, superclass of StreamReader and StringReader
 
// Read from plain text file if it exists
theSourceFile = new FileInfo (Application.dataPath + "/puzzles.txt");
if ( theSourceFile != null && theSourceFile.Exists )
{
   reader = theSourceFile.OpenText();  // returns StreamReader
}
else
{
   // try to read from Resources instead
   TextAsset puzdata = (TextAsset)Resources.Load("puzzles", typeof(TextAsset));
   reader = new StringReader(puzdata.text);  // returns StringReader
}
if ( reader == null )
{
   Debug.Log("puzzles.txt not found or not readable");
}
else
{
   // Read each line from the file/resource
   while ( (string txt = reader.ReadLine()) != null )
   Debug.Log("-->" + txt);
}
	
	}
	

	}

Try moving the declaration of ‘txt’ out of those parens, maybe it’s getting scoped. Also you should indicate which line it’s complaining on

string txt;
txt = reader.ReadLine();
while (txt != null)
{
  Debug.Log("-->"+txt);
  txt = reader.ReadLine();
}