Answers for "css hover function"

on hover css

/* Changes an element's color on hover */

.selector {
	background-color: black;
}

.selector:hover {
	background-color: blue;
}

javascript on hover

<img onmouseover="enlargeImage(this)" border="0" src="smiley.gif" alt="Smiley" width="32" height="32">

<script>
function enlargeImage(x) {
  x.style.height = "64px";
  x.style.width = "64px";
}
</script>