function is(variable) {
	return (typeof(variable) != 'undefined' && variable != null);
}

function changeLocation(address, newWindow) {
	if(newWindow){
		var oWindow = window.open(address, '_blank');
		if(oWindow.focus) {
			oWindow.focus();
		}        
	}else{
		if(is(window.location)) {
			window.location.href = address;
		} else {
			window.src = address;
		}        
	}
}
/**
 * Zatrzymuje babelkowanie czyli propagowanie JS zdarzen 
 * @param {Event} event
 */
function stopEventPropagation(event){
	if (event.stopPropagation) {
		event.stopPropagation();
	} else {
		event.cancelBubble = true;
	}
}