How to keep my navigation bar stick to the top?

[kubisztal]

Im trying to get my nagivation bar to stick to the top of the page but cant for some reason. I tried looking up and i tried a few things but they didnt work.

body {background-color:black;}
     ul {
     list-style-type: none;
     margin: -8;
     padding-bottom: 0px;
     padding-top: 0px;
     overflow:hidden;
     background-color:rgb(235,0,0);
     margin-top: 5px;
     font-family: ariel;
     }
    li {
     padding-left: 35%;
    }
    li a {
    display: inline;
    float: left;
    text-decoration: none;
    padding-left: 25px;
    padding-top: 20px;
    padding-right: 25px;
    padding-bottom: 20px;
    }
    li a:link{
    color:white;
    text-decoration: none;
    }
    li a:visited{
    color:purple;
    text-decoration: none;
    }
    li a:hover{
    background-color:rgb(200,0,0);
    text-decoration: none;
    margin: auto;
    }
    li a:active{
    color:rgb(100,100,100);
    text-decoration: none;
    }

As you can see i use ul,li and a href tags to make the nav bar and to get it in a horizontal form i use float: left Thanks!

[Exequiel]

just put this to your css in ul

position: fixed;

[kubisztal]

Hey, thanks a lot for help :)