滑鼠移動div

js:

var isDrag = 0;
var divMove;
 var divAndMouseX;//滑鼠落點距離div左上方x座標的差距  
var divAndMouseY;//滑鼠落點距離div左上方y座標的差距  
function down(div) {
    isDrag = 1;
    divMove = div;
    divAndMouseX = event.clientX - parseInt(document.getElementById(div).offsetLeft);
    divAndMouseY = event.clientY - parseInt(document.getElementById(div).offsetTop);
}
function up() {
    isDrag = 0;
}
function move() {
    if (isDrag == 1) {
        document.getElementById(divMove).style.left = event.clientX - divAndMouseX;
        document.getElementById(divMove).style.top = event.clientY - divAndMouseY;
    }

}

html:

<div id="tip" onmousedown="down(this.id)" onmousemove="move()" onmouseup="up()">