哪错了．．．．

[male110]

var f=document.form1;
var usrName=f.userName.value;

用户名:<input type="text" id="userName" name="userName" value="">
提示userName为空或不是对像...

[ruan_hg]

那你输入个值再试试看
或var usrName=document.GetElemengById("userName").value;

[kkun_3yue3]

var usrName=document.getElementById("userName");
alert(usrName.value);

[dxphero]

通过document.GetElemengById("userName").Value来获取值

[tank299281]

var f=document.form1("userName");
alert(f.value );

[male110]

错误找到了．．．
　<script>写成了<scrip