Set page header for every content page from Master Page

Suppose you have a div with a lebel in the master page, and dynamically assign text for that label (as header)  from the content page's title.
It is one of the simple way for set header, here  'PgTitle' is the label id. and the code is like :
    
    this.PgTitle.Text = Page.Title;

-- that should be written in page load of master page