function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    };
  }
}

function toggleLayer(whichLayer) {
	var element = document.getElementById(whichLayer);
	var theDisplayStyle = element.style.display;
	if (theDisplayStyle === 'none') {
		element.style.display = 'block';
	}
	else {
		element.style.display = 'none';
	}
}

function printLink() {
	if (window.print) {
    	window.print();
    } else {
    	alert('Unfortunately your browser doesn\'t support printing via Javascript.\nTo print this page please select "File > Print..." in your browser\'s menu.');
    }
	return false;
}

var shown = "text1";  
function showitem(item) {        
  if (document.getElementById) { 
                document.getElementById(shown).style.display = "none";           
                document.getElementById(item).style.display = "block"; 
                shown = item;  
                return false;  
        }               
}