如何修复php文件中的页眉和页脚

I am Developing a code using php . In which I am importing two files (header.php and footer.php) in another php file index.php. Now I want that header.php and footer.php should be fixed while scrolling horizontally. can you suggest me the code. I am using the following code

Header.php
 code here
footer.php
code here 

index.php

<?php include("header.php"); ?>
 welcome to index file 
 welcome to index file 
 welcome to index file 

<?php include("footer.php"); ?>

In this file index.php, I want that header and footer should be fixed while scrolling horizontally and others css should also not be disturbed.

try this.,

 <div id="header">
    <?PHP include_once('header.php');?>
    </div>
    <div id="wrap">
    welcome to index file
    </div>
    <div id="footer">
    <?PHP include_once('foo.php');?>
    </div>

css:

#header{position:fixed;top:0px;}
#footer{position:fixed;bottom:0px;}

or

header.php 
<div id ="header"></div><div id="content">
footer.php
</div><div id="footer"></div>

index.php
<?PHP include_once('header.php');?>
 content here.,
<?PHP include_once('footer.php');?>

Your solucion is ok. only i recomend use something like this:

<div id="header">
<?PHP include_once('header.php');?>
</div>
<div id="wrap">
here is my html content
</div>
<div id="footer">
<?PHP include_once('foo.php');?>
</div>

the use of include_once is for not repeat the include of some file and with a good css obtains a excelent layout

use HTML5 and use include_once

<header>
<?PHP include_once('header.php');?>
</header>
<div id="wrap">
here is my html content
</div>
<footer>
<?PHP include_once('foo.php');?>
</footer>

Here is just a sample FIDDLE DEMO

html,body{
    margin:0;padding:0;
}
header{
    background:Green;
    height:50px;
}
footer{
    position:absolute;
    width:100%;
    bottom:0;
    background:Red;
    height:50px;
}

In your css, just put the following attribute: position:fixed; and that should do the trick.