js表单验证实例
<form id="loginform" method="post" action="post.php教程" style="margin:0px; padding:0px;" >
<table width="400" border="0" align="center" cellpadding="0" cellspacing="0" style="line-height:30px;">
<tr>
<td height="30" align="right"><font style="color:#f6892e; font-weight:bold">·</font>您的姓名(*)：</td>
<td height="30" align="left" ><input type="text" name="name" id="name" class="sub2"></td>
</tr>
<tr>
<td height="30" align="right"><font style="color:#f6892e; font-weight:bold">·</font>电 话(*)：</td>
<td height="30" align="left"><input type="text" name="tel" id="tel" class="sub2"></td>
</tr>
<tr>
<td height="30" align="right"><font style="color:#f6892e; font-weight:bold">·</font>您的常用qq(*)：</td>
<td height="30" align="left"><input type="text" name="cardid" id="cardid" class="sub2"></td>
</tr>
<tr>
<td height="30" align="right" style=" vertical-align: middle"><font style="color:#f6892e; font-weight:bold">·</font>您的购买需求：</td>
<td height="30" align="left">
<textarea name="bz" cols="30" style="height:50px;"></textarea>
</td>
</tr>
<input name="type" type="hidden" value="jhzsky" />
<tr>
<td height="30" colspan="2" align="center"><input type="submit" value="提交报名"></td>
</tr>
<tr>
<td height="30" colspan="2" align="center" id="checkinfo"></td>
</tr>
</table>
</form>
<script type="text/网页特效">
var form=document.getelementbyid("loginform");
form.onsubmit=function(){
if(form.name.value==""){
document.getelementbyid("checkinfo").innerhtml="姓名不能为空";
return false;
}
if(form.tel.value==""){
document.getelementbyid("checkinfo").innerhtml="电话号码不能为空";
return false;
}
var patrn=/(^0[0-9]{2,3}-[1-9]{8}$)|[1-9]{7,8}|(^0?1[0-9]{10}$)/;
if (!patrn.exec(form.tel.value)) {
document.getelementbyid("checkinfo").innerhtml="电话号码不合法";
return false;
}
if(form.cardid.value==""){
document.getelementbyid("checkinfo").innerhtml="qq号码不能为空";
return false;
}
var request=getrequest();
if(request){
var formdata="floorname="+form.floorname.value+"&pass="+form.pass.value;//构造发送数据字符串
request.open("get","save.php?"+formdata,true);
request.onreadystatechange=function(){
callback(request);//指定回调函数
}
request.send(null);
}
return false;//阻止表单按常规方式提交
}
</script>
补充：网页制作,js教程 
