Simple C # Validation class

Using System;
Using System.Text.RegularExpressions;
Namespace Bobomousecom.crm
{
<summary>
Summary description of the regexlib.
</summary>
public class Regexlib
{
Public Regexlib ()
{
//
TODO: Add constructor logic here
//
}

Search the input string and return all href= "..." values
String Dumphrefs (String inputstring)
{
Regex R;
Match m;
R = new Regex ("href\\s*=\\s*: \" (? <1>[^\ "]*") | (? <1>\\s+)) ",
regexoptions.ignorecase|regexoptions.compiled);
for (M = R.match (inputstring); m.success m = M.nextmatch ())
{
Return ("Found href" + m.groups[1]);
}
}

Verify email address
BOOL IsValidEmail (String strin)
{
Return true if Strin are in valid e-mail format.
Return Regex.IsMatch (Strin, @ "^" ^ [\w-\.] +) @ (\[[0-9]{1,3}\. [0-9] {1,3}\. [0-9] {1,3}\.) | (([\w-]+\.) +)) ([a-za-z]{2,4}| [0-9] {1,3}) (\]?) $");
}

The Dd-mm-yy date form replaces the Mm/dd/yy date form.
String mdytodmy (String input)
{
return Regex.Replace (Input, "\\b (? \\d{1,2})/(? \\d{1,2})/(? \\d{2,4}) \\b", "${day}-${month}-${year}");
}

Verify that you are a decimal
BOOL Isvaliddecimal (String strin)
{

return Regex.IsMatch (strin,@ "[0].\d{1,2}|[ 1] ");
}

Verify that you are a phone number
BOOL Isvalidtel (String strin)
{
return Regex.IsMatch (strin,@) (\d+-)? ( \d{4}-?\d{7}|\d{3}-?\d{8}|^\d{7,8}) (-\d+)? ");
}

Date verified
BOOL Isvaliddate (String strin)
{
return Regex.IsMatch (strin,@ "^2\d{3}-" (?: 0?) [1-9]|1[0-2])-(?: 0? [1-9]| [1-2]\d|3[0-1]) (?: 0? [1-9]|1\d|2[0-3]):(?: 0? [1-9]| [1-5]\d):(?: 0? [1-9]| [1-5]\d) $ ");
}

Verify suffix Name
BOOL Isvalidpostfix (String strin)
{
return Regex.IsMatch (strin,@ "\. i:gif|jpg) $ ");
}

Verify that the characters are between 4 and 12
BOOL Isvalidbyte (String strin)
{
return Regex.IsMatch (strin,@ "^[a-z]{4,12}$");
}

Verifying IP
BOOL Isvalidip (String strin)
{
return Regex.IsMatch (strin,@ "^ (\d{1,2}|1\d\d|2[0-4]\d|25[0-5]) \. ( \D{1,2}|1\D\D|2[0-4]\D|25[0-5]) \. (\d{1,2}|1\d\d|2[0-4]\d|25[0-5]) \. (\d{1,2}|1\d\d|2[0-4]\d|25[0-5]) $ ");
}
}
}