<div id="Button"></div>
<script>
var MD=false;
var ns=navigator.appName=="Netscape";
document.onmousemove=function()
{
  if(MD) 
    document.getElementById("Button").innerHTML="按下左键的移动";
  else
    document.getElementById("Button").innerHTML="未按下左键的移动";
}
document.onmousedown=function(e)
{
  e=e||event;
  if(ns&&e.button==0)//ff左键
    MD=true;
  else if(e==1)//ie左键
    MD=true;
}
document.onmouseup=function()
{
  MD=false;
  document.getElementById("Button").innerHTML="";
}
</script>