IE与Firefox的HTC

test.htm

<style>
span {-moz-binding: url(test.xml#custom);behavior:url(test.htc);cursor:pointer;background:#ddd;}
</style>
<span> test </span>

//IE
test.htc

<attach event="onmouseup" onevent="up()"/>
<attach event="onmousedown" onevent="down()"/>
<script language="javascript">
var currX = 0;
function up(){
 alert(currX);
}
function down(){
 currX += 1;
}
</script>

//Firefox
test.xml

<?xml version="1.0"?>
<bindings xmlns="http://www.mozilla.org/xbl" xmlns:html="http://www.w3.org/1999/xhtml">
 <binding id="custom" styleexplicitcontent="true">
  <implementation>
   <property name="currX">0</property>
  </implementation>
  <handlers>
   <handler event="mousedown">
    this.currX = event.clientX+this.currX;
   </handler>
   <handler event="mouseup">
    alert(parseInt(this.currX));
   </handler>
  </handlers>
 </binding>
</bindings>