this is written by jquery, the key jquery code:
/ to achieve drag special effects /
var div1 =document.getElementById("faqdiv");
var disX = 0;
var disY = 0;
$(div1).css("margin","0"); //div
document.onmousedown = function (ev) { //
var oEvent = ev || event; //
disX = oEvent.clientX - div1.offsetLeft; //divoffsetLeft
disY = oEvent.clientY - div1.offsetTop; //divoffsetTop
document.onmousemove = function (ev) { //
var oEvent = ev || event;
var left = oEvent.clientX - disX; //div
var top = oEvent.clientY - disY; //div
if (left < 0) { //divDIV
left = 0;
}else if (left > document.documentElement.clientWidth - div1.offsetWidth) {
left = document.documentElement.clientWidth - div1.offsetWidth;
}
if (top < 0) {
top = 0;
}else if (top > document.documentElement.clientHeight - div1.offsetHeight) {
top = document.documentElement.clientHeight - div1.offsetHeight;
}
div1.style.left = left + "px"; //DIV
div1.style.top = top + "px"; //DIV
}
document.onmouseup = function () { //
document.onmousemove = null;
document.onmouseup = null;
}
return false;
}