js获取div编辑框，textarea，input text的光标位置，兼容FF和IE

<h<!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> 
<title>js获取div编辑框，textarea，input text的光标位置，兼容FF和IE</title> 
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript"> 
//去除左右所有空格 
String.prototype.trim = function () { 
return this.replace(/(^s*)|(s*$)/g, ""); 
} 
function getPosition(element) {
var OsObject = ""; 
if (navigator.userAgent.indexOf("MSIE") > 0) { 
OsObject = "MSIE"; 
} 
if (navigator.userAgent.indexOf("Firefox") > 0) { 
OsObject = "Firefox"; 
} 
if (navigator.userAgent.indexOf("Safari") > 0) { 
OsObject = "Safari"; 
} 
if (navigator.userAgent.indexOf("Camino") > 0) { 
OsObject = "Camino"; 
} 
if (navigator.userAgent.indexOf("Gecko") > 0) { 
OsObject = "Gecko"; 
} 
if (navigator.userAgent.indexOf("Chrome") > 0) { 
OsObject = "Chrome"; 
}
var result = 0;
if (!document.selection) { //非IE浏览器 
var thisTagName = null;
if ($(element).attr("tagName") != "TEXTAREA" && $(element).attr("tagName") != "INPUT") {
if ($(element).attr("tagName") == "DIV" && $(element).attr("contenteditable") == "true") {
thisTagName = window.getSelection().anchorNode.parentElement.tagName; 
}
else { 
thisTagName == null; 
} 
} 
else { 
if ($(element).attr("tagName") == "INPUT" && $(element).attr("type") == "text") { 
thisTagName = window.getSelection().anchorNode.tagName; 
} 
else { 
console.log(window.getSelection()); 
thisTagName = window.getSelection().anchorNode.tagName; 
} 
} 
console.log(thisTagName); 
if (thisTagName == "TEXTAREA" || thisTagName == "INPUT" || (thisTagName=="BODY"&&OsObject == "Chrome")) { 
result = element.selectionStart 
}
else if (thisTagName != null) { 
if (thisTagName == element.tagName) { 
if (window.getSelection().anchorNode.textContent == $(element).text()) { 
result = window.getSelection().anchorOffset; 
} 
else { 
var currentIndex = window.getSelection().anchorOffset; 
var txt = ""; 
var txtoo = window.getSelection().anchorNode.previousSibling; 
while (txtoo != null) { 
txt += txtoo.textContent; 
txtoo = txtoo.previousSibling; 
}
result = txt.trim().length + currentIndex; 
} 
} 
else { 
var currentIndex = window.getSelection().anchorOffset; 
var txt = ""; 
var txtoo = window.getSelection().anchorNode.parentElement.previousSibling; 
while (txtoo != null) { 
txt += txtoo.textContent; 
txtoo = txtoo.previousSibling; 
} 
result = txt.trim().length + currentIndex; 
} 
}
else { 
return 0; 
} 
} else { //IE 
var rng; 
if ($(element).attr("tagName") == "TEXTAREA" || ($(element).attr("tagName") == "INPUT" && $(element).attr("type") == "text") || ($(element).attr("tagName") == "DIV" && $(element).attr("contenteditable") == "true")) { 
element.focus(); 
rng = document.selection.createRange(); 
rng.moveStart('character', -element.innerText.length); 
var text = rng.text; 
for (var i = 0; i < element.innerText.length; i++) { 
if (element.innerText.substring(0, i + 1) == text.substring(text.length - i - 1, text.length)) { 
result = i + 1; 
} 
} 
} 
else { 
return 0; 
} 
} 
return result; 
}
function getValue(element) { 
var pos = getPosition(element); 
document.getElementById("pnum").value = pos; 
}
</script> 
<style type="text/css"> 
#Div1, #Div2 
{ 
width: 500px; 
height: 100px; 
border: solid 1px black; 
} 
</style> 
</head> 
<body> 
<input id="pnum" type="text" value="Hello,wellcome to test! 你好,欢迎测试!" onmouseup="getValue(this)" 
style="display: block" /> 
<textarea cols="60" rows="10" onkeyup="getValue(this)" onmouseup="getValue(this)">Hello,wellcome to test! 你好,欢迎测试! 注意源代码开闭合标记之间不能换行，否则统计错误！</textarea> 
<div id="Div1" onclick="getValue(this);" onkeyup="getValue(this);" contenteditable="true">一二三<span>四五</span>六七八<span>九零</span> 注意源代码开闭合标记之间不能换行，否则统计错误！注意div编辑框源码里面是嵌套有其他标签的，可以正常返回正确位置！</div> 
<br /> 
<div id="Div2" onclick="getValue(this);" onkeyup="getValue(this);">一二三四五六<span>七八</span></div> 
</body> 
</html>