<form action="login.do?act=login" method="post">

　　<input type="submit" name="submit1" value="登陆">

</form>  

<form action="login.do?act=login" name="myform" method="post">

　　<input type="button" name="submit1" value="登陆" onclick="javascript:document.myform.submit();" >

</form>