在IE６和Firefox里下面的代码显示的有差别,该怎么修改下面的代码

在IE６和Firefox里下面的代码显示的有差别，就是兼容性问题，是不是下面的代码写的不规范啊？ 如果是的话，该怎么修改下面的代码，才能不出现兼容性的问题。

php page code

<div id="container">
<div class="logo">
<img src="/images{script_path}logo.png" alt="" />
</div>
<div id="box">
<form id="loginForm" action="" method="POST" onsubmit="return false;">
<p class="main">
<label>Username: </label>
<input name="user_login_id" value="" /> 
<label>Password: </label>
<input type="password" name="user_login_passwd" value="">
</p>

<p class="space">
<span><input type="checkbox" id="remember_me"/> <label for="remember_me">Remember me</label></span>
<input type="submit" value="Login" class="login" />
</p>
</form>
</div>
<div id="box" align="right">
<button name="btn_init" style="width:100px;">
激活帐号
</button>
</div>
</div>

css code

@import 'css3.css';
* { margin:0; padding:0;}

body {
position:relative;
height:100%;
background:#fff url('/images/user/login/loginbg.png') left top repeat-x;
font-family:Tahoma, Arial, sans-serif;
}

img {
border:0;
}

#container {
width:960px;
margin:0 auto;
}

#container .logo {
width:230px;
margin:240px auto 0;
}

#container #box {
clear:both;
float:none;
width:70%;
margin:50px auto 0;
}

p.main label {
float:left;
padding:5px;
display:inline;
margin-left:40px;
font-size:13px;
color:#000;
margin-right:10px;
}

#box p {
clear:both;
float:none;
width:100%;
}

p.main INPUT {
background:url('/images/user/login/input.png') 0 0 repeat-x;
border:1px solid #d3d3d3;
color:#555;
padding:5px;
float:left;
width:200px;
}

input.login {
float:right;
padding:3px 10px 3px 10px;
color:#fff;
font-size:12px;
text-decoration:none;
border:1px solid #555;
background:url('/images/user/login/rep1.png') 50% 50% repeat-x;
display:inline;
margin-right:5px;
cursor:pointer;
}

span {
font-size:13px;
color:#666;
}

.space {
padding-top:15px;
}

span input {
margin-left:125px;
margin-right:5px;
border:1px solid #111;
background:#444;
color:#fff;
}

help help help thank you