//把注释编码
text = text.replace(/\n/g,'\r').replace(//g,function($0, text)
{
var ret = '';
//alert(ret);
return ret;
}).replace(/\r/g,'\n');

//调整格式
var rgx = /\n(<(([^\?]).+?)(?:\s|\s*?>|\s*?(\/)>)(?:.*?(?:(?:(\/)>)|(?:<(\/)\2>)))?)/mg;
var nodeStack = [];
var output = text.replace(rgx,function($0,all,name,isBegin,isCloseFull1,isCloseFull2 ,isFull1,isFull2){
var isClosed = (isCloseFull1 == '/') || (isCloseFull2 == '/' ) || (isFull1 == '/') || (isFull2 == '/');
//alert([all,isClosed].join('='));
var prefix = '';
if(isBegin == '!')
{
prefix = getPrefix(nodeStack.length);
}
else
{
if(isBegin != '/')
{
prefix = getPrefix(nodeStack.length);
if(!isClosed)
{
nodeStack.push(name);
}
}
else
{
nodeStack.pop();
prefix = getPrefix(nodeStack.length);
}

}
var ret = '\n' + prefix + all;
return ret;
});

var prefixSpace = -1;
var outputText = output.substring(1);
//alert(outputText);

//把注释还原并解码，调格式
outputText = outputText.replace(/\n/g,'\r').replace(/(\s*)/g,function($0, prefix, text)
{
//alert(['[',prefix,']=',prefix.length].join(''));
if(prefix.charAt(0) == '\r')
prefix = prefix.substring(1);
text = unescape(text).replace(/\r/g,'\n');
var ret = '\n' + prefix + '';
//alert(ret);
return ret;
});

return outputText.replace(/\s+$/g,'').replace(/\r/g,'\r\n');
}
function getPrefix(prefixIndex)
{
var span = ' ';
var output = [];
for(var i = 0 ; i < prefixIndex; ++i)
{
output.push(span);
}

return output.join('');
}
function btnFormat_click()
{
var $ = document.getElementById;
$('output').value = formatXml($('input').value);
}