diff --git a/sortt.js b/sortt.js
index 5113738..ca220c0 100644
--- a/sortt.js
+++ b/sortt.js
@@ -7,15 +7,7 @@
 */
 
 //safe url sort param global
-window.sortt_url=window.location.search;
-if (window.sortt_url.indexOf("sort=") < 0) {
-  //no sort url argument found
-  window.sortt_url="";
 
-} else {
-  window.sortt_url=window.sortt_url.substr(window.sortt_url.indexOf("sort=")+5);
-  window.sortt_url=window.sortt_url.substr(0,window.sortt_url.indexOf("&"));
-}
 //creat global function with main routine
 window.sortt=function(normsort,revsort,isdefault){
   //sortTable [normsort] (revsort) (isdefault)
@@ -26,8 +18,22 @@ window.sortt=function(normsort,revsort,isdefault){
   //default values of optinal parameters
   if (typeof revsort  === 'undefined') revsort = "";
   if (typeof isdefault  === 'undefined') isdefault = false;
+  if (!(typeof isdefault  === 'boolean')) isdefault = false;
 
   // look at ReadMe
   console.log("sortTable() normsort:\"" + normsort + "\" revsort:\"" + revsort + "\" sortdefault:\"" + sortdefault + "\"");
 
+  // parse URL
+  url_sort="";
+  if (window.location.search.indexOf("sort=") < 0) {
+    if ( isdefault ) url_sort = normsort;
+  } else {
+    url_sort=window.location.search.substr(window.location.search.indexOf("sort=")+5);
+    url_sort=url_sort.substr(0,url_sort.indexOf("&"));
+  }
+
+
+
+
+
 };