[spo]

Справился

$("input").keydown(function(event) {
	// Allow only backspace and delete
	if ( event.keyCode == 46 || event.keyCode == 8 ) {
		// let it happen, don't do anything
	}
	else {
		// Ensure that it is a number and stop the keypress
		if (event.keyCode < 48 || event.keyCode > 57 ) {
			event.preventDefault();	
		}	
	}
});