// prevent ctrl + s
		$(document).bind('keydown', function(e) {
		if(e.ctrlKey && (e.which == 83)) {
		e.preventDefault();
		return false;
		}
		});

		document.addEventListener('contextmenu', event => event.preventDefault());

		document.onkeydown = function(e) {
		if (e.ctrlKey && 
		(e.keyCode === 67 ||   
		//e.keyCode === 86 || 
		e.keyCode === 85 || 
		e.keyCode === 117)) {
		return false;
		} else {
		return true;
		}
		};
		$(document).keypress("u",function(e) {
		if(e.ctrlKey)
		{
		return false;      }
		else {
		return true;
		}});