how to add custom buttons in (HtmlEditorExtender)

Hi, i have two problems in Ajax HtmlEditorExtender 

1 - that  when i save the text and it's go to my database it's come with html tags is there is a way to remove the tags before it saves in the database 

2 - i want to add custom buttons in the HtmlEditorExtender i want to add emoji(Emotion) like this web site http://ajaxtoolkit.net/HTMLEditor/OtherSamples/EditorWithCustomButtons_1.aspx but i didn't know how to add it 

i'm using :

VS 2012 ,SQL SERVER 2012 EntityFramework

this is images from my HtmlEditorExtender 

http://www11.0zz0.com/2017/03/04/19/744555252.png

http://www11.0zz0.com/2017/03/04/19/554652647.png

http://www11.0zz0.com/2017/03/04/19/259991860.png

and this is when i save the html tags comes with me like in this image in the database

http://www4.0zz0.com/2017/03/04/19/833813527.png