Try this code You may want something like this
<button class="normal" id="myButton"
value="Hover" onmouseover="mouseOver()"
onmouseout="mouseOut()">Some text</button>
Then on your .js file enter this.Make sure your html is connected to your .js
var tag=document.getElementById("myButton");
function mouseOver() {
tag.style.background="yellow";
};
function mouseOut() {
tag.style.background="white";
};