CodingForums.com - Nav menu links overlapping

Ok so this may be my first post but i am pretty good with html and css but i am having a serious problem getting my links to work properly in any browser.

http://www.kennethitalbot.netai.net/...ting/index.php

as you can see this website is still in it's very basic building faze

but my links are overlapping when they drop down to the next level. is there a way i can fix this.

here is my code

Code:

<--HTML-->

        <nav>

                <ul>

                    <li><a href="home.php">Home</a></li>

                <li><a href="events.php">Upcoming Events</a></li>

                <li><a href="members.php">Our Memebers</a></li>

                <li><a href="games.php">Games</a></li>

                <li><a href="comps.php">Current Competitions</a></li>

                <li><a href="help.php">Help</a></li>

                <li><a href="sponser.php">Sponser Us</a></li>

                <li><a href="admin.php">Administrator Login</a></li>

            </ul>

        </nav>





<--CSS-->

nav {

        width:700px;

        height:150px;

        border: solid 1px #000;

        text-align:center;

        margin-left:5px;

}



nav ul {

        list-style-type:none;

        margin:5;

        padding:0;

        padding-top:6px;

        padding-bottom:6px;

}



nav ul li {

        display:inline;

        height:30px;

        margin:5;

}



nav ul li a:link,a:visited {

        font-weight:bold;

        color:#FFFFFF;

        background-color:#98bf21;

        text-align:center;

        padding:6px;

        text-decoration:none;

        text-transform:uppercase;

}



nav ul li a:hover,a:active {

        background-color:#7A991A;

}

I apreciate any help i could get.

Thanks in advance