A Pen by mrmoje.

A-Pen-by-mrmoje.markdown

A Pen by mrmoje

A Pen by mrmoje on CodePen.

License.

index.html

<button id="login" onmouseover="turnWhite()">
  Login Button. MouseOver to turn white
</button>

script.js

document.getElementById("login").onmouseover = function () { turnWhite(); }

function turnWhite(){  
    var myEventElement = turnWhite.caller.arguments[0].target;
    myEventElement.className = "white";
}

style.css

#login{
  background:black;
  color:white;
}

#login.white{
  background:white;
  color:black;
}