var interval = 0;
var opcity = 0;	

function fadeIn(elemento) {
	const elem = document.querySelector(elemento);	
	if (elem) {
	  elem.style.display = 'block';	
	  interval=setInterval(() => {
		opacity = Number(window.getComputedStyle(elem).getPropertyValue("opacity"));			
		if(this.opacity < 1) {
			this.opacity += 0.1;
			elem.style.opacity = opacity;			
		}
		else {
			clearInterval(interval);
		}
	  }, 30);	
	}	
} 

function fadeOut(elemento) {
	clearInterval(interval);
	const elem = document.querySelector(elemento);
	if (elem) {
	  opacity = Number(window.getComputedStyle(elem).getPropertyValue("opacity"));
	  interval=setInterval(() => {
		opacity = Number(window.getComputedStyle(elem).getPropertyValue("opacity"));
		if(opacity > 0) {
			opacity -= 0.1;
			elem.style.opacity = opacity;
		}
		else {
			clearInterval(interval);
			elem.style.display = 'none';
		}
	  }, 30);
	}	
}