请问如何获取下面这个需要登录的系统里面的网页？

<script type="text/javascript" src="./platform/js/md5.js"></script>
<script type="text/javascript" src="./resources/js/adapter/ext/ext-base.js"></script>
<script type="text/javascript" src="./resources/js/ext-core.js"></script>
<script type="text/javascript" >
Ext.onReady(function(){
function initPage(){
//定位表单
var formDiv = Ext.get('formDiv');
var centerPos = formDiv.getCenterXY();
formDiv.setLocation( centerPos[0], centerPos[1] );
var formPosX = formDiv.getLeft();
var formPosY = formDiv.getTop();

//默认定位到用户名
var formDiv = Ext.get('username').focus();
}

function logon(){
var realPwdInput = document.getElementById('realPwd');
var usernameInput = document.getElementById('username');
var pwdInput = document.getElementById('pwd');
var realPwd = realPwdInput.value;
var username = usernameInput.value;
var pwd = "";

if( username=="" ){
document.getElementById('inputFeedback').innerText = '请输入【用户名】！';
usernameInput.focus();
return;
}
if( realPwd=="" ){
document.getElementById('inputFeedback').innerText = '请输入【口令】！';
realPwdInput.focus();
return;
}
pwd = MD5( realPwd );
pwdInput.value = pwd;
Ext.get('logonForm').dom.submit();
}

initPage();

Ext.get('submitBtn').on( 'click', logon ); Ext.getBody().on( 'keydown', function(e){
var k = e.getKey();
if( k == e.ENTER ){
logon();
return;
}
else{
// alert(k);
}
});

/*
Ext.get('logonTable').unselectable();
var inputs = Ext.query('input');
Ext.each(inputs, function(item, i, allItems){
var el = Ext.get( item );
el.removeAllListeners();
return true;
});
*/
});
</script>
</head>
<body class="cls-logon-body"><div id="formDiv">
<form id="logonForm" name="logonForm" action="./logon.do" method="post">
<table width="1000" border="0" align="center" cellpadding="0" cellspacing="0" class="cls-logon-form" id=logonTable>
  <tr>
    <td>
    <table width="500" border="0" align="right" cellpadding="0" cellspacing="0">
      <tr>
        <td width="100%" height="30" align="center" colspan="4" style="color:#f00;" id="inputFeedback">
        
         <input id="tryTimes" name="tryTimes" value="1" type="hidden" />

        

        
        </td>
      </tr>
      <tr>
        <td width="60" align="left"></td>
        <td width="20" height="50" align="right"><img src="./resources/image/slate/logon/username-icon.gif" width="31" height="32" /></td>
        <td width="60" align="right" class="cls-logon-prompt">用户名:</td>
        <td width="360">
         <input id="username" name="username" type="text" class="cls-logon-text" style="width:250px;"/>
        </td>
      </tr>
      <tr>
        <td width="60" align="left"></td>
        <td width="20" height="50" align="right"><img src="./resources/image/slate/logon/pwd-icon.gif" width="30" height="31" /></td>
        <td width="60" align="right" class="cls-logon-prompt">口&nbsp;&nbsp;令:</td>
        <td width="360">
         <input id="realPwd" name="realPwd" type="password" class="cls-logon-text" style="width:250px;"/>
         <input id="pwd" name="pwd" type="hidden" />
        </td>
      </tr>
      <tr>
        <td colspan="4" height="20"></td>
      </tr>
      <tr>
        <td colspan="4" align="left">
         <table width="100%" border="0" cellpadding="0" cellspacing="0">
           <tr>
        <td width="250">&nbsp;</td>
        <td><input id="submitBtn" type="button" class="cls-logon-button" value="登录" /></td>
        <td width="250">&nbsp;</td>
      </tr>
    </table>
         </td>
        </tr>
      <tr>
        <td colspan="4"></td>
      </tr>
    </table>
    </td>
  </tr>
</table>
</form>
</div>