clientX, clientY是鼠标当前相对于网页的位置，当鼠标位于页面左上角时clientX=0, clientY=0；
offsetX, offsetY是鼠标当前相对于网页中的某一区域的位置，当鼠标位于页面中这一区域的左上角时offsetX=0, offsetY=0；
screenX, screenY是相对于用户显示器的位置
x,y是鼠标相对于当前浏览器的位置
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD><TITLE>Measure for Measure</TITLE> <SCRIPT> <!-- function one() { report.value = "The DIV above is relatively positioned in the BODY. The style object contains the information that was set in the inline style to position this object. The following are the values that would be reported for the various position and dimension properties on the style object for the DIV:" + " "; report.value= report.value + " mydiv.style.top (string) = " + foodiv.style.top + " "; report.value= report.value + " mydiv.style.left (string) = " + foodiv.style.left + " "; report.value= report.value + " mydiv.style.height (string) = " + foodiv.style.height + " "; report.value= report.value + " mydiv.style.width (string) = " + foodiv.style.width + " "; report.value= report.value + " mydiv.style.pixelTop (long) = " + foodiv.style.pixelTop + " "; report.value= report.value + " mydiv.style.pixelLeft (long) = " + foodiv.style.pixelLeft + " "; report.value= report.value + " mydiv.style.pixelHeight (long) = " + foodiv.style.pixelHeight + " "; report.value= report.value + " mydiv.style.pixelWidth (long) = " + foodiv.style.pixelWidth + " "; report.value= report.value + " mydiv.style.posTop (long) = " + foodiv.style.posTop + " "; report.value= report.value + " mydiv.style.posLeft (long) = " + foodiv.style.posLeft + " "; report.value= report.value + " mydiv.style.posHeight (long) = " + foodiv.style.posHeight + " "; report.value= report.value + " mydiv.style.posWidth (long) = " + foodiv.style.posWidth + " "; } function two() { report.value = "Each object has a set of offset positions. The offset properties for the positioned darkBlue DIV above are: "; report.value= report.value + " offsetLeft = " + foodiv.offsetLeft + " "; report.value= report.value + " offsetTop = " + foodiv.offsetTop + " "; report.value= report.value + " offsetHeight = " + foodiv.offsetHeight + " "; report.value= report.value + " offsetWidth = " + foodiv.offsetWidth + " "; report.value= report.value + " offsetLeft = " + document.body.offsetLeft + " "; report.value= report.value + " offsetTop = " + document.body.offsetTop + " "; report.value= report.value + " offsetHeight = " + document.body.offsetHeight + " "; report.value= report.value + " offsetWidth = " + document.body.offsetWidth + " "; } function three() { report.value = "Scroll values for the darkBlue DIV object" + " "; report.value= report