有鼠标位置获取元素

　document.elementFromPoint(x,y)可以获得x和y坐标处的元素的引用;

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

<svg width="100%" height="100%" version="1.1"
xmlns="http://www.w3.org/2000/svg">

<script>
function create_a(evt)
{
   alert(123);
   var left = evt.screenX;


   var top = evt.screenY;


   var client_x = evt.clientX;
   var client_y = evt.clientY;



   alert("left="+left);
   alert("top="+top);

   alert("client_x=" + client_x);
   alert("client_y=" + client_y);

   var obj = document.elementFromPoint(left,top);
   alert("obj=" + obj);
   alert("obj.id=" + obj.id);
    alert("obj.nodeName=" + obj.nodeName);

   var obj2 = document.elementFromPoint(client_x,client_y);
   alert("obj2=" + obj2);
   alert("obj2.id=" + obj2.id);
   alert("obj2.nodeName=" + obj2.nodeName);



/*
//var SVGDoc=evt.getTarget().getOwnerDocument();
var SVGDoc=evt.target.ownerDocument;
var txt=SVGDoc.getElementById("txt");
var link=SVGDoc.createElement("a");
var text_node=SVGDoc.createTextNode("LINK");

link.setAttributeNS(
"http://www.w3.org/1999/xlink",
"xlink:href",
"http://www.w3schools.com");

link.appendChild(text_node);
txt.appendChild(link);
*/
}
</script>

<text id="txt" x="10" y="10">Click on the circle to create a ....</text>
<circle id = "circle_1" cx="20" cy="40" r="1.5em" style="fill:blue" onclick="create_a(evt)"/>

</svg>