Try this

<script language="JavaScript">
function changeColour(evt) {
eye1 = evt.target.ownerDocument.getElementById("eye1")
eye1.style.setProperty("fill","red")
}
</script>

<path id="eyeLast" onclick="changeColour(evt)"
d="M 80 70 L 60 85 80 100 z"
style="stroke:black; stroke-width:3; fill:blue" />
<circle id="eye1" cx="520" cy="300" r="20" style="fill:blue" />

See
http://www.learnsvg.com/tutorial2/ex...etProperty.svg

Michel