function changeURLPar(url, ref, value) {
var str = "";
if (url.indexOf('?') != -1)
str = url.substr(url.indexOf('?') + 1);
else
return url + "?" + ref + "=" + value;
var returnurl = "";
var setparam = "";
var arr;
var modify = "0";
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;
}