header.php

<style>

div#nav{
  text-align: center;
}
div#nav ul{
  display: inline-block;
}

	/* Add a black background color to the top navigation */
.topnav {
		background-color: #333;
		overflow: hidden;
		}

	/* Style the links inside the navigation bar */
.topnav a {
			float: left;
			color: #f2f2f2;
			text-align: center;
			padding: 14px 122.4px;
			text-decoration: none;
			font-size: 17px;
}

	/* Change the color of links on hover */
.topnav a:hover {
			background-color: #ddd;
			color: black;
}

	/* Add a color to the active/current link */
.topnav a.active {
			background-color: #191970;
			color: white;
}

.center{
			display: block;
			float:center;
}

</style>

    <marquee><h1>Police Emergency Service System</h1></marquee>

<div class="topnav">
  <a class="active" href="#home">Log Call</a>
  <a href="#update">Update</a>
  <a href="#signin">Sign In</a>
  <a href="#signout">Sign Out</a>
</div>