change html DOCTYPE in my website

change html DOCTYPE in my website

References

Reference NO 1

http://stackoverflow.com/questions/13585505/change-html-doctype-in-my-website

Reference NO 2

http://stackoverflow.com/questions/8973897/is-it-safe-to-simply-change-web-page-doctype-html-4-01-or-xhtml-1-0-to-doctype-h

Reference NO 3

http://webdesign.about.com/cs/doctype/a/aaquirksmode.htm

Reference NO 4

http://www.w3schools.com/html/html_intro.asp

Reference NO 5

http://www.htmlgoodies.com/html5/markup/the-doctype-tag-and-its-effect-on-page-rendering.html

Reference NO 6

http://www.javascriptkit.com/howto/doctype.shtml

Reference NO 7

http://validator.w3.org/docs/help.html

Reference NO 8

http://reference.sitepoint.com/html/doctypes