[j0hnik]

<input type="number"/>
	<script>
		var time; 
		document.querySelector('input').addEventListener('input', function(e){
			clearTimeout(time);
			time = setTimeout(()=>{
				if(this.value > 1000) this.value = 1000;
				else if(this.value < 20) this.value = 20;
			},1000);
		});
	</script>