//只能填英文和数字
function IsDigit()
{
  return ((event.keyCode >= 48) && (event.keyCode <= 57));
}
//后台登陆验证
function chkadmin_log(form){
	
  if (form.admin_user.value=="")
 	 {
	   alert("请输入用户名.");
	   form.admin_user.focus();
	   return false;
 	 }
  if (form.admin_user.value.length<3||form.admin_user.value.length>12)
 	 {
	   alert("用户名为3到12位.");
	   form.admin_user.focus();
	   return false;
 	 }
  if (form.admin_pwd.value=="")
 	 {
	   alert("请输入密码.");
	   form.admin_pwd.focus();
	   return false;
 	 }
  if (form.admin_pwd.value.length<3||form.admin_pwd.value.length>18)
 	 {
	   alert("密码为3到18位.");
	   form.admin_pwd.focus();
	   return false;
 	 }
  if (form.ValidCode.value=="")
 	 {
	   alert("请输入验证码.");
	   form.ValidCode.focus();
	   return false;
 	 }
  if (form.ValidCode.value.length!= 4)
 	 {
	   alert("验证码只能位4位.");
	   form.ValidCode.focus();
	   return false;
 	 }
}
//修改管理密码表单验证
function admin_pwd_mod(form){
  if (form.admin_pwd.value=="")
 	 {
	   alert("请输入原始密码.");
	   form.admin_pwd.focus();
	   return false;
 	 }
  if (form.admin_pwd.value.length<3||form.admin_pwd.value.length>18)
 	 {
	   alert("密码为3到18位.");
	   form.admin_pwd.focus();
	   return false;
 	 }
  if (form.admin_pwd1.value=="")
 	 {
	   alert("请输入新密码.");
	   form.admin_pwd1.focus();
	   return false;
 	 }
  if (form.admin_pwd1.value.length<3||form.admin_pwd1.value.length>18)
 	 {
	   alert("密码必须为3到18位.");
	   form.admin_pwd1.focus();
	   return false;
 	 }
  if (form.admin_pwd2.value=="")
 	 {
	   alert("请再次输入新密码以便确认.");
	   form.admin_pwd2.focus();
	   return false;
 	 }
  if (form.admin_pwd1.value != form.admin_pwd2.value)
 	 {
	   alert("两次输入密码不一致，请检查.");
	   form.admin_pwd2.focus();
	   return false;
 	 }
}