//数字字符
public static string KeepNum(string str)
{
char[] tmp = new char[str.Length];
char[] s = str.ToCharArray();
for (int i = 0, j = 0; i < str.Length; i++)
{
if (s[i] >= '0' && s[i] <= '9')
{
tmp[j] = s[i];
j++;
}
}
return new string(tmp);
}
<input type="text" id="mobile" runat="server" maxlength="12" onkeyup="value=value.replace(/[^\d]/g,'')" />
asax文件：
<%@ Control Language="c#" AutoEventWireup="false" Codebehind="counter.ascx.cs" Inherits="JiAnWeb.counter" TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>
<LINK href="css.css" rel="stylesheet">
<FONT face="宋体">
<TABLE id="table_coun ......
