JavaScript changes background, hide, and style

Javascript

How does JavaScript change background, hide, and style? See the following function, getElementById is an ID element taken. JavaScript is sensitive to capitalization, so pay special attention to it!

function Gongqiu2 ()
{
document.getElementById ("GYLB1"). style.display= ' none ';//Hide
document.getElementById ("Gylb2"). style.display= ';//Show
document.getElementById ("Lbtd1"). bgcolor= ' #ffffff ';/Set background color
document.getElementById ("Lbtd2"). Classname= ' font12 '; Change Style
}