Mr X,

 

In the version 5.x, we've removed the functions which allow you set page properties in the server side.

 

For the client side, you need to write your own code. Here are some tips:

 

    // get the cute editor instance
    var editor1 = document.getElementById('<%=Editor1.ClientID%>');
    
    //Get the editor content 
    var editdoc=editor1.GetDocument();

 

    //Get the editor content head
    var head = editdoc.getElementsByTagName("head")[0];