异步应验数据是否存在

<script type="text/javascript">
	function loadXMLDoc(value,appId)
	{
		$.ajax({
			   type: "POST",
			   url: "${basePath}/app/developers/ajaxCheckCanvasPageUrl",
			   data: "value="+value+"&appId="+appId,
			   success: function(msg){
			     alert( "Data Saved: " + msg );
			   }
			 });
	}
	
	$(function() { 
		 var _area = $('input#publicCanvasUrl'); 
		 _area.bind('keyup change', function() { //绑定keyup和change事件 
			 loadXMLDoc($("#publicCanvasUrl").val(), $("#appId").val());
		 }); 
		 });
	
</script>