<script language="vbScript">
<!--验证输入是否合法
sub yanzheng(usercodestr)
dim theform
set theform=document.form1
if trim(theform.username.value)="" then
alert("请输入您的用户名!")
theform.username.focus()
theform.username.value=""
elseif instr(trim(theform.username.value),"'")>0 then
alert("用户名中不能包含单引号'!请重新输入.")
theform.username.focus()
theform.username.value=""
elseif theform.password.value="" then
alert("请输入您的密码!")
theform.password.focus()
elseif instr(theform.password.value,"'")>0 then
alert("密码中不能包含单引号'!请重新输入.")
theform.password.focus()
theform.password.value=""
elseif theform.yzm.value="" then
alert("请输入验证码!")
theform.yzm.focus()
elseif ucase(theform.yzm.value)<>ucase(usercodestr) then
alert("您输入的验证码不正确!请重新输入.")
theform.yzm.focus()
theform.yzm.value=""
else
theform.submit()
end if
end sub
-->
</script>
<form name="form1" method="post" action="sys_login.asp">
<tr>
<td height="26" colspan="3" align="center" valign="top"> <input type="button" name="login" value="登录"