if (str.indexOf('&') != -1) {
arr = str.split('&');

for (i in arr) {
  if (arr[i].split('=')[0] == ref) {
    setparam = value;
    modify = "1";
  }
  else {
    setparam = arr[i].split('=')[1];
  }
  returnurl = returnurl + arr[i].split('=')[0] + "=" + setparam + "&";
}

returnurl = returnurl.substr(0,returnurl.length - 1);

if (modify == "0")
  if (returnurl == str)
    returnurl = returnurl + "&" + ref + "=" + value;

}
else {
if (str.indexOf('=') != -1) {
arr = str.split('=');

  if (arr[0] == ref) {
    setparam = value;
    modify = "1";
  }
  else {
    setparam = arr[1];
  }
  returnurl = arr[0] + "=" + setparam;
  if (modify == "0")
    if (returnurl == str)
      returnurl = returnurl + "&" + ref + "=" + value;
}
else
  returnurl = ref + "=" + value;

}
return url.substr(0,url.indexOf('?')) + "?" + returnurl;
}

function delQueStr(url,ref) //删除参数值
{
var str = "";

if (url.indexOf('?') != -1)
str = url.substr(url.indexOf('?') + 1);
else
return url;
var arr = "";
var returnurl = "";
var setparam = "";
if (str.indexOf('&') != -1) {
arr = str.split('&');
for (i in arr) {
if (arr[i].split('=')[0] != ref) {
returnurl = returnurl + arr[i].split('=')[0] + "=" + arr[i].split('=')[1] + "&";
}
}
return url.substr(0,url.indexOf('?')) + "?" + returnurl.substr(0,returnurl.length - 1);
}
else {
arr = str.split('=');
if (arr[0] == ref)
return url.substr(0,url.indexOf('?'));
else
return url;
}
}