Hi, I know the problem but I don't know how to fix this. This is JQuery image slider and I used digit as my ID attribute but unfortunately, W3C invalid returns because:

Line 222, Column 18: value of attribute "id" invalid: "1" cannot start a name

In this case, I know that I cannot use digit as my id but the code makes me to use that id... please give me some advice on this thank you

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
  <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.18/jquery-ui.min.js"></script>
  <script type="text/javascript">

	function Slider(){
		$(".slider #1").show("fade", 500);
		$(".slider #1").delay(5500).hide("slide", {direction: 'left'}, 500);
		var sc = $(".slider img").size();
		var count = 2; 
		setInterval(function (){
			$(".slider #"+count).show("slide", {direction: 'right'}, 500);
			$(".slider #"+count).delay(5500).hide("slide", {direction: 'left'}, 500);
			if(count == sc){
				count = 1;
				count = count + 1;
		}, 6500);

  <div class="slider">
        <img id="1" src="images/slide0.png" border="0" alt="error" />
        <img id="2" src="images/slide1.png" border="0" alt="error" />