JS分析URL字符串，取得参数名，AJAX传参请求代码示例

//当前页面URL中参数分析函数，正则校验
function getQueryString(name) {
    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
    var r = window.location.search.substr(1).match(reg);
    if (r != null) return unescape(r[2]); return null;
    }

function zan()
{
//取得想要的参数值，getQueryString中的参数为String型，传入参数名为URL中参数名，即可获得
	var docchannel = getQueryString("docchannel");
    var docid = getQueryString("docid");
var xmlhttp;
if (window.XMLHttpRequest)
  {//  for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {//  for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("zanspan").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","./manager/zan+1.jsp?t="+Math.random()+"&docid="+docid+"&docchannel="+docchannel+"",true);
xmlhttp.send();
}