Accessing Master page functions from a content page

Accessing Master page functions from content page we must include a MasterType directive at the top of the Content page ASPX file:

<%@ MasterType virtualpath="~/DetailsMaster.master" %>

In DetailsMaster.master.cs page
public void SavePageData()
{
// function definition
}

After place the MasterType directive is in place in the Content page, then public functions in the Master page are available to the Content page code.

C# Code:
//Call the SavePageData function from the Master page
Master.SavePageData();

I hope it will helpfull for other developer.