function changeHREF(url, pname, pvalue, todel) {
if(url==""){url = window.location.href;}
if(todel==undefined) {var todel = new Array();}
for(i=0;i<todel.length;i++){
	if (url.indexOf(todel[i]+"=") != -1) {
	  var before = url.substring(0, url.indexOf(todel[i]+"=")-1);
	  var after = url.substring(url.indexOf(todel[i]+"="));
	  if (after.indexOf('&') != -1)
	   after = after.substring(after.indexOf("&"), after.length);
	  else
	   after = "";	
	url = before + after;
	}
}
//alert(url);
	
 if (url.indexOf(pname+"=") != -1) {
  var before = url.substring(0, url.indexOf(pname+"="));
  var after = url.substring(url.indexOf(pname+"="));
  if (after.indexOf('&') != -1)
   after = after.substring(after.indexOf("&"), after.length);
  else
   after = "";
   gohere = before + pname + "=" + pvalue + after;
   	if(gohere.indexOf("?")==-1){
		pos=gohere.indexOf("&");		
		if(pos!=-1) gohere = gohere.substr(0,pos)+"?"+gohere.substr(pos+1,gohere.length);
	}
  return gohere;
 } else{
    gohere = url+(url.indexOf("?")=="-1"?"?":"&")+pname+"="+pvalue
  return gohere;
 }
}