multipages jquery mobile background image help

multipages jquery mobile background image help

i have jquery mobile index.html that conatins many pages page1,2,3,4,5 etc. my problem is i cant get different background image on each page. hi can you please tell me what i am doing wrong.thank you
this is the code i have used. it oesnt work no background on the page i decide to put it in.
some of my code

<!DOCTYPE html>
<html lang="en">
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="css/jquery.mobile-1.4.5.min.css">
<script src="js/jquery-1.11.3.min.js"></script>
<script src="js/jquery.mobile-1.4.5.min.js"></script>
<meta charset="utf-8"/>
</head>
<body>
<style>

.ui-page6
{
background-image: url("./img/ima.png");
background-size: 100% 100%;
height: 100%;
position: absolute;
width: 100%;
}
</style>

<div data-role="page" id="page6">
<div data-role="header">
<h1>form</h1>
</div>

<div data-role="main" class="ui-content">