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

function print_preview() {
	// Switch the stylesheet
	setActiveStyleSheet('Print Preview');
	
	// Create preview message
	add_preview_message();

	// Print the page
	window.print();
}

function add_preview_message(){
var main_content = document.getElementById('content-layout');
var main_body = main_content.parentNode;

	if (document.getElementById){
		
//		var preview_message = document.createElement('div');
//		preview_message.id = 'preview-message';
	
		// Create Heading
//		var preview_header = document.createElement('h3');
//		var preview_header_text = document.createTextNode('This is a print preview of this page');
		//preview_header.appendChild(preview_header_text);
		
		// Create paragraph
//		var preview_para = document.createElement('p');
//		var preview_para_text = document.createTextNode('This message block won\'t print though. ');
		
//		var cancel_function_link = document.createElement('a');
		//	cancel_function_link.onclick = function(){ cancel_print_preview(); return false; };
		//	cancel_function_link.setAttribute('href', '#');	
//		var cancel_function_link_text = document.createTextNode('Return to the existing page.');
		//cancel_function_link.appendChild(cancel_function_link_text);
		//preview_para.appendChild(preview_para_text); //
		//preview_para.appendChild(cancel_function_link);
		
		// Put it all toegether
		//preview_message.appendChild(preview_header); 
		//preview_message.appendChild(preview_para);
		//main_body.insertBefore(preview_message, main_content);
	}
}

function cancel_print_preview() {
	// Destroy the preview message
//	var print_preview = document.getElementById('preview-message');
//	var main_body = print_preview.parentNode;
//	main_body.removeChild(print_preview);
	
	// Switch back stylesheet
	setActiveStyleSheet('default');
}

function setActiveStyleSheet(title) {
   var i, a, main;
   for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
     if(a.getAttribute("rel").indexOf("style") != -1
        && a.getAttribute("title")) {
       a.disabled = true;
       if(a.getAttribute("title") == title) a.disabled = false;
     }
   }
}