<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> <script type="text/javascript"> window.onload=function() { var oDiv=document.getElementById('div1'); oDiv.onmousedown=function(ev) { var oEvent=ev||event; var x=0; var y=0; x=oEvent.clientX-oDiv.offsetLeft; y=oEvent.clientY-oDiv.offsetTop; document.onmousemove=function(ev) { var oEvent=ev||event; var out1=oEvent.clientX-x; var out2=oEvent.clientY-y; var oWidth=document.documentElement.clientWidth-oDiv.offsetWidth; var oHeight=document.documentElement.clientHeight-oDiv.offsetHeight; if(out1<0) {out1=0;} else if (out1>oWidth) { out1=oWidth; } if(out2<0) {out2=0;} else if (out2>oHeight) { out2=oHeight; } oDiv.style.left=out1+'px'; oDiv.style.top=out2+'px'; } document.onmouseup=function() { document.onmousemove=null; document.onmouseup=null; } return false;//解决firefox低版本的bug问题 } } </script> </head>