document.getElementById("box").onmousedown =function(e)        {            if (e.button==0)            {                this.style.background="#c00";            }            else if(e.button==1)            {               this.style.background="#0c0";            }            else if(e.button==2)            {              this.style.background="#00c";            }            else            {                alert("你按下了"+e.button+"号键");            }             console.log(e.type);             console.log(e.screenX);             console.log(e.clientX);             console.log(e.offsetX);}

        document.onkeydown=function(e)        {            if (e.ctrlKey)            {                alert("你按下了ctrl键");            }             else if (e.altKey)            {                alert("你按下了alt键");            }            else  if (e.shiftKey)            {                alert("你按下了shift键");            }             else if (e.ctrlKey &&altKey &&shiftKey)            {                alert("你按下了三个键");            }             console.log(e.type);        }

var textbox=document.getElementById("textbox");   var val=‘‘;   document.getElementById("box").onmousedown=function(e)   {    e=window.event || e;    val="e.screenX: "+e.screenX+       "\ne.screenY: "+e.screenY+        "\nclientX: "+e.clientX+    //clientX支持所有浏览器         "\nclientY: "+e.clientY+   //          "\ne.X: "+e.X+           "\ne.Y: "+e.Y+            "\npageX: "+e.pageX+             "\npageY: "+e.pageY+              "\noffsetX: "+e.offsetX+               "\noffsetY: "+e.offsetY+               "\noffsetX: "+(e.clientX-this.offsetLeft);                    textbox.value=val;                    //offset火狐不支持                    //可以用此方法                    //e.clientX-offsetleft                }

//html代码

<div id="box"> </div>
<textarea id="textbox" style="display:block;margin:50px auto;width:400px;height:200px;"></textarea>