How to underline $10 and $50

using System;
using System.Text.RegularExpressions;

class Test
{
    public static void Main()
    {
        string pattern = @"\$\d+";
        Regex rgx = new Regex(pattern);

        // Here is the string you got from the DB
        string inputStr = "All Customers Take $10 off $50 in ccc.com's Home Decor, Home Appliances and Outdoor Store! Valid through 5/31/2012";

        // Surround the $number matches with spans that will add under line (styled HTML markup)
        string outputStr = rgx.Replace(inputStr, "<span style=\"text-decoration:underline\">$&</span>" );

        // Display the resulting string.
        Console.WriteLine("Pattern:       \"{0}\"", pattern);
        Console.WriteLine("Input string:  \"{0}\"", inputStr);
        Console.WriteLine("Output string: \"{0}\"", outputStr);
    }
}

what you want from us??? What I understand is that you want to underline the text. solution for this is as below:

All Customers Take $10 off $50 in ccc.com's Home Decor, Home Appliances and Outdoor Store! Valid through 5/31/2012"