function shareOnFacebook(u, t, i, d){
	if(d == null) d = '';
	var params = 'u=' + escape(u) + '&t=' + escape(t) + '&i=' + escape(i) + '&d=' + escape(d);
	var fbsharer = 'http://www.facebook.com/sharer/sharer.php?u=' + escape('http://' + location.host + '/?' + params);
	window.open(fbsharer,'fbsharer','toolbar=0,status=0,width=500,height=500');
}

function shareOnTwitter(u, t, d){
	if(d == null) d = '';
	else d = ' : ' + d;
	var params = 'text=' + t + d + ' ---> ' + '&url=http://' + location.host + '/?u=' + u;
	var twsharer = 'http://twitter.com/share?' + params;
	window.open(twsharer,'twsharer','toolbar=0,status=0,width=500,height=500');
}