function checkbrowser() {
	browsertype = navigator.userAgent.toLowerCase();
	
	if (browsertype.indexOf('msie') != -1)	{
		 browser = "isIE";
		 return browser;
   }
	else if (browsertype.indexOf("netscape") != -1) {
	 	 browser = "isNS";
	 	 return browser;			 
	}		
}
							 
function show_extras	($source) {
	
	if (document.getElementById($source).style.display == 'block') {
	  document.getElementById($source).style.display = 'none'
	  document.getElementById('content').style.opacity = '0.4'
	}
	else {
		document.getElementById($source).style.display = 'block';
      document.getElementById('content').style.opacity = '0.4'
	}		
}