How to read columns of a tab delimited text file.

I need to read each column value of a tab delimited file.
The file is retrieved.
The column values are not returned.
What do I need to modify?
Thanks,

Source file:
Tab delimited

Date      OldExchange      OldSymbol      NewExchange      NewSymbol
20120315      OTCBB            REFGD      OTCBB            REFG
20120315      OTCBB            SRWY      OTCBB            SRWYD
20120309      OTCBB            ALDFF      AMEX            AXX
20120307      OTCBB            SRCPD      NASDAQ            SRCP

I need to get the column values of each column.

str1 = value of first column "20120315";
str2 = value of 2nd column "OTCBB";
etc.

This is what I have now:
 while ((line = sr.ReadLine()) != null)
        {
            values = line.Split(new char[] { ',' });
            values[values.Length - 1] = values[values.Length - 1].Trim(new char[] { '"' });

           
values[0];
//Returns values[0] as "20120315\tOTCBB\tREFGD\tOTCBB\tREFG"

values[1];
//error Index was outside the bounds of the array.

How do I return the actual column values?