我想用如下的验证程序,验证用户名和密码是否有输入,提交后如果无输入,则在相应对话框旁边显示红色标记。但是无输入提交后,没有红色标记显示,可能是JAVASCRIPT脚本编写错误,应如何修改呢?
<HTML>
<HEAD>
<h3>客户端脚本数据验证模式实例</h3>
<script language="javascript">
function jsCheck()
{
if(document.myform.userid.value=='')
document.myform.erruid.style.visibility='visible';
else if(document.myform.passwd.value=='')
document.myform.errpwd.style.visibility='visible';
else
document.myform.action='newform.aspx';
}
</script>
</HEAD>
<BODY>
<form name="myform" method="post" onsubmit="jsCheck()">
<table cellspacing="0" cellpadding="1" border="0">
<tr valign="top">
<td align="left">用户名:</td>
<td><input name="userid" type=text></td>
<td><span id="erruid" style="VISIBILITY:hidden;COLOR:red">请输入用户名</span></td>
</tr>
<tr valign="top">
<td align="left">密码:</td>
<td><input name="passwd" type=password></td>
<td><span id="errpwd" style="VISIBILITY:hidden;COLOR:red">请输入密码</span></td>
</tr>
</table>
<input type="submit" value="提交">
</form>
</BODY>
</HTML>
<HTML>
<HEAD>
<h3>客户端脚本数据验证模式实例</h3>
<script language="javascript">
function jsCheck()
{
if(document.myform.userid.value=='')
document.myform.erruid.style.visibility='visible';
else if(document.myform.passwd.value=='')
document.myform.errpwd.style.visibility='visible';
else
document.myform.action='newform.aspx';
}
</script>
</HEAD>
<BODY>
<form name="myform" method="post" onsubmit="jsCheck()">
<table cellspacing="0" cellpadding="1" border="0">
<tr valign="top">
<td align="left">用户名:</td>
<td><input name="userid" type=text></td>
<td><span id="erruid" style="VISIBILITY:hidden;COLOR:red">请输入用户名</span></td>
</tr>
<tr valign="top">
<td align="left">密码:</td>
<td><input name="passwd" type=password></td>
<td><span id="errpwd" style="VISIBILITY:hidden;COLOR:red">请输入密码</span></td>
</tr>
</table>
<input type="submit" value="提交">
</form>
</BODY>
</HTML>
<HEAD>
<h3>客户端脚本数据验证模式实例</h3>
<script language="javascript">
function jsCheck()
{
if(document.myform.userid.value=="")
{
document.all("erruid").style.visibility="visible";
return(false);
}
else if(document.myform.passwd.value=="")
{
document.all("errpwd").style.visibility="visible";
return(false);
}
else
{
document.myform.action="newform.aspx";
return(true);
}
}
</script>
</HEAD>
<BODY>
<form name="myform" method="post" onsubmit="return(jsCheck());">
<table cellspacing="0" cellpadding="1" border="0">
<tr valign="top">
<td align="left">用户名:</td>
<td><input name="userid" type=text></td>
<td><span id="erruid" style="VISIBILITY:hidden;COLOR:red">请输入用户名</span></td>
</tr>
<tr valign="top">
<td align="left">密码:</td>
<td><input name="passwd" type=password></td>
<td><span id="errpwd" style="VISIBILITY:hidden;COLOR:red">请输入密码</span></td>
</tr>
</table>
<input type="submit" value="提交">
</form>
</BODY>
</HTML>