// get an object by id
function get(id) {
return document.getElementById(id);
}

// change location
function cloc(loc, keys, vals) {
loc=loc.replace(/&/g,'&');
loc=setprms(loc,keys,vals);
document.location.href=loc;
return false;
}

// submit location
function sloc(form, loc, keys, vals) {
loc=loc.replace(/&/g,'&');
loc=setprms(loc,keys,vals);
get(form).action=loc;
get(form).submit();
return false;
}

// return true on enter
function enter(e) {
  key = window.event ? window.event.keyCode : e.which;
  return(key==13);
}

// set location parameters
function setprms(loc, keys, vals) {
for(i=0; i<keys.length; i++)
  loc=setprm(loc,keys[i],vals[i]);
return loc;
}

// set a location parameter
function setprm(loc, name, value) {
id=loc.indexOf('&'+name+'=');
if(id==-1)
  id=loc.indexOf('?'+name+'=');
if(id!=-1){
  id++;
  id_e=loc.indexOf('&',id);
  if(id_e==-1)
    id_e=loc.length;
  old_val=loc.substring(id+name.length+1,id_e);
  loc = loc.replace(name+'='+old_val, name+'='+value);
}
else
  loc+=(loc.indexOf('?')!=-1?'&':'?')+name+'='+value;
//alert(loc.replace(/&/g,'\n&'));
return loc;
}