图片验证码

这是显示验证码的代码：
<%
randomize
yzm=int(8999*rnd()+1000)
function code()
    a=int(yzm/1000)
    b=int((yzm-a*1000)/100)
    c=int((yzm-a*1000-b*100)/10)
    d=int(yzm-a*1000-b*100-c*10)
    response.write "<img align=center height=15 border=0 src=img/number/" & a & ".gif>"
    response.write "<img align=center height=15 border=0 src=img/number/" & b & ".gif>"
    response.write "<img align=center height=15 border=0 src=img/number/" & c & ".gif>"
    response.write "<img align=center height=15 border=0 src=img/number/" & d & ".gif>"
end function
%>

请问怎样来用text里的值和验证码图片做验证啊？请帮忙写个js函数演示一下。谢谢 咯。               

                                                                                     3QU

[ 本帖最后由 liangfengfen 于 2010-8-24 21:13 编辑 ]