Global methods in C# ASP.Net

Question

I´m using C# and ASP.NET for developing in Windows Azure.

I want to do a global Method to validate fields, my idea is to do a global Method like (for example in Site.Master)

static Regex dateRegex = new Regex("^\\d{2}/\\d{2}/\\d{4}$");
public boolean validate( string type, string stringToValdate)
{
  boolean valid = NO;
  if (type = "date")
  {
      Match m = fechaRegex.Match(stringToValdate);
      if(m.Success)
      {
            valid = true;
      }
  }

 return valid;
}

And then use it in another webform

using ????

Site.Master.validate("date",TextBox1.Text);

Answer 1

You can use Extension Method on Master Type

public static class Extension
{ 
    public static boolean Validate(this Master master, 
                                   string type, 
                                   string stringToValdate)
    {
      boolean valid = NO;
      if (type = "date")
      {
          Match m = fechaRegex.Match(stringToValdate);
          if(m.Success)
          {
                valid = true;
          }
      }

     return valid;
    }
}

Use Case :

using NamesPaceOfExtension;

Site.Master.Validate("date",TextBox1.Text);