javascript验证输入的是不是5到15的数字…… 帮看看那里出错啦…… 运行没反应呀！

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'begin.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page">  <script type="text/javascript"> function checkNumber() { var number = document.getElementsByName("number")[0]; if(number.length < 1) { alert("请输入!"); number.focus(); return false; } for(var i=0; i<number.length; i++) { var chNo = "0123456789"; if(chNo.indexOf(number.charAt(i)) == -1) { alert("请输入数字！"); number.focus(); return false; } } if(parseInt(number.value)<5 || parseInt(number.value)>15) { number.value = 10; } return true; } </script> </head> <body> <form name="form1" onsubmit="return checkNumber();"> 请输入5到15中的任意一个数：<br/> <input type="text" name="number" /><br/> <input type="submit" value="提交"/> </form> </body> </html>

答案：错在你一会儿用number当dom对象一会儿又它当成值。

修改后的代码：	

    <script type="text/javascript">
	function checkNumber()
	{
	
	var number = document.getElementsByName("number")[0].value;
	
	if(number.length < 1)
		{
			alert("请输入!");
			number.focus();
			return false;
		}
	for(var i=0; i<number.length; i++)
		{
			var chNo = "0123456789";
			if(chNo.indexOf(number.charAt(i)) == -1)
			{
				alert("请输入数字！");
				number.focus();
				return false;
			}
		}
		
	if(parseInt(number)<5 || parseInt(number)>15)	
	{
		document.getElementsByName("number")[0].value = 10;
	}
			
	return true;
		
	}
	</script>

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