function OnChange(dropdown)
{
	var myDropdown = document.getElementById(dropdown);
	var myindex  = myDropdown.selectedIndex
	var SelValue = myDropdown.options[myindex].value
	
	var curCon = gup('conductor');
	var curOrc = gup('orchestra');

	if(dropdown=='conductor') {
		curCon=SelValue;
		var baseURL  = "?action=show_discography&conductor="+curCon;
	} else {
		curOrc=SelValue;
		var baseURL  = "?action=show_discography&key="+curOrc+"";
	}
	top.location.href = baseURL;
	return true;
}

function gup( name )
{
  var regexS = "[\\?&]"+name+"=([^&#]*)";
  var regex = new RegExp( regexS );
  var tmpURL = window.location.href;
  var results = regex.exec( tmpURL );
  if( results == null )
    return "";
  else
    return results[1];
}