Question

I’m trying to write a facebook like chatbox, but i’ve encountered a small problem.
I’m using the following code (it’s only test code, so it’s not really clean):

css code:

#messenger {
  position: fixed;
  bottom: 0px;
  right: 10px;
  width: 200px;
  height: 300px;
  z-index: 4;
  background-color: #ECECEC;
  border: 1px solid #000;
}
#messenger.p {
  text-align: right;
}
#contacts {
  margin: 5px 5px 5px 5px;
}
#chatspace {
  position: fixed;
  bottom: 0px;
  right: 240px;
  height: 20px;
  left: 20px;
  background-color: #ECECEC;
  border: 1px solid #000;
  z-index: 4;
}
.chatbox {
  position: absolute;
  bottom: 0px;
  width: 200px;
  height: 200px;
  z-index: 4;
  background-color: #ECECEC;
  border: 1px solid #000;
}

html/javascript code:

<script type="text/javascript">
var i = 0;

function oc_chatbox() {

  if (i == 0) {
  document.getElementById('contacts').style.visibility = 'hidden';
  document.getElementById('messenger').style.height = '20px';
  i = 1;
  }

  else {
  document.getElementById('contacts').style.visibility = 'visible';
  document.getElementById('messenger').style.height = '300px';
  i = 0;
  }
}

function new_chat(userid) {
  var new_right;
  new_right = document.getElementById('messenger').style.right;
  //alert('old value: '+ new_right);
  new_right += 20;
  //alert('New value of right: '+ new_right);
  document.getElementById('chatspace').innerHTML = '<div id="'+userid+'" class="chatbox" style="right: '+new_right+'px;"></div>';
  //document.write('<div id="'+userid+'" class="chatbox" style="right: '+new_right+'px;"></div>');
}
</script>
<div id="chatspace"></div>
<div id="messenger">
 <p><a href="#" onclick="oc_chatbox();">Collapse</a></p>
 <div id="contacts">
 <ul>
  <li><a href="#" onclick="new_chat('contact_a');">contact A</a></li>
 </ul>
 </div>
</div>

the problem is, that when I try to add new chats to the chatbar, i can’t seem the place them next to each other.
anyone who can help ?

EDIT:

so i changed to javascript code to:

var last = null;
function new_chat(userid) {
  if(userid==null)
    userid = "user666";
  var new_right;
  var margin = 10;
  var messenger = window.last==null?document.getElementById('messenger'):window.last;  //Take the messenger or the last added chat
  new_right = document.body.clientWidth-messenger.offsetLeft;      //Compute the window size
  console.log(new_right);                                //Log the number
  new_right += margin;                                   //keep spaces between divs

  var newChat = document.createElement("div");           //DOM create DIV
  newChat.id = userid;
  newChat.className = "chatbox shadow";
  newChat.style.right = new_right+"px";
  newChat.innerHTML = '<p>'+userid+'</p><p><textarea></textarea></p>';
  window.last = newChat;  //Remember whichever is last
  document.body.appendChild(newChat);
} 

and now it works, thanks !

Answer 1

You cannot get an element right offset using its style, unlest the style is set and valid. Instead you must get element.offsetLeft and size of window area and do this:

new_right = windowSize()[0]-messenger.offsetLeft;

Where window size is this function.

Here is my, working, version of your function:

var last = null;
function new_chat(userid) {
  if(userid==null)
    userid = "user666";
  var new_right;
  var margin = 20;
  var messenger = window.last==null?document.getElementById('messenger'):window.last;  //Take the messenger or the last added chat
  new_right = windowSize()[0]-messenger.offsetLeft;      //Compute the window size
  console.log(new_right);                                //Log the number
  new_right += margin;                                   //keep spaces between divs

  var newChat = document.createElement("div");           //DOM create DIV
  newChat.id = userid;
  newChat.className = "chatbox";
  newChat.style.right = new_right+"px";
  window.last = newChat;  //Remember whichever is last
  document.body.appendChild(newChat);
} 

You may get errors if console is not defined in your brouwser. But in such case you should take a better browser. Normally, the if(console!=null) is put in code.
And here is the link.