zoom out problem

zoom out problem

I am facing zoom in  problem mobile native apps. When I hit on input section my page is zoom in but when i fill out the form or cancel button the page still zoom in. I want it to normal screen please guide me.

I am usking code:

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="target-densitydpi=device-dpi, width=device-width, initial-scale=0" />

<title>Emodoki</title>
<link rel="stylesheet" media="screen and (-webkit-device-pixel-ratio: 1.0)" href="css/emodoki_mdpi.css" />
<link rel="stylesheet" media="screen and (-webkit-device-pixel-ratio: 1.5)" href="css/emodoki_hdpi.css" />
<!--<link rel="stylesheet" media="screen and (-webkit-device-pixel-ratio: 0.75)" href="css/emodoki_ldpi.css" />
-->
 <link rel="stylesheet" href="master.css" type="text/css" media="screen" title="no title">
 <script type="text/javascript" charset="utf-8" src="cordova-2.0.0.js"></script>
 <script type="text/javascript" charset="utf-8" src="main.js"></script>
 <script type="text/javascript" charset="utf-8" src="childbrowser.js"></script>

<script src="http://cufon.shoqolate.com/js/cufon-yui.js" type="text/javascript"></script>
<script src="js/two-turtle-doves.cufonfonts.js" type="text/javascript"></script>
<script src="js/Roboto_400.font.js" type="text/javascript"></script>

<script type="text/javascript">
Cufon.replace('.what_is_your_mood', { fontFamily: 'Two Turtle Doves', hover: true, textShadow:'0px 1px #39535d', color:'#fffe03' });
Cufon.replace('.click_your_mood', { fontFamily: 'Roboto' });
</script>

</head>
<body>
<header class="logo"></header>
<section >
  <header class="social_login">
    <a href="javascript:;" class="login_fb"></a>
    <a href="javascript:;" class="login_twitter"></a>
    <a href="javascript:;" class="login_googleplus"></a>
  </header>
  <div class="yellow_text center margin_20px">Or Sign In using your Emodoki account</div>
  <ul class="login_form">
    <li><input type="text" name="textfield" id="textfield" placeholder="Username"></li>
    <li><input type="password" name="textfield" id="textfield" placeholder="Password"></li>
    <li>
      <input type="submit" name="button" id="button" value="Login" class="login_btn">
    </li>
    <li><a href="javascript:;" class="yellow"><strong><u>Forgot Password?</u></strong></a></li>
    <li><strong>Don't have a Emodoki account yet?</strong></li>
    <li><input type="submit" name="button" id="button" value="Sign Up" class="signup_btn"></li>
  </ul>
</section>

</body>
</html>