Centreren van popup.

 <script language="javascript">
 function pop_window(url) {
 //remove a attribute if you don't want it to show up
  var popit = window.open(url,'console','scrollbars,width=700,height=480');
 }
</script>

<script language="javascript">
 function pop_window(url) {
 //remove a attribute if you don't want it to show up
  var popit = window.open(url,'console','scrollbars,width=700,height=480');
 }
</script>

<script language="javascript">
var venster = null;
function NieuwVenster(mijnPagina,mijnNaam,breedte,hoogte,scroll){
VanafLinks = (screen.width)? (screen.width-breedte) /2 : 0;
VanafBoven = (screen.height)?(screen.height-hoogte)/2 : 0;
instellingen =
'height='+hoogte+',width='+breedte+',top='+VanafBoven+',left='+VanafLinks+',scrollbars='+scroll+',directories, location, menubar, resizable, status, toolbar'
venster = window.open(mijnPagina,mijnNaam,instellingen)}
</script>

<script language="javascript">
var venster = null;
function NieuwVenster(mijnPagina,mijnNaam,breedte,hoogte,scroll){
VanafLinks = (screen.width)? (screen.width-breedte) /2 : 0;
VanafBoven = (screen.height)?(screen.height-hoogte)/2 : 0;
instellingen =
'height='+hoogte+',width='+breedte+',top='+VanafBoven+',left='+VanafLinks+',scrollbars='+scroll+',directories, location, menubar, resizable, status, toolbar'
venster = window.open(mijnPagina,mijnNaam,instellingen)}
</script>

<a href="#" onclick="NieuwVenster(this.href,'naam','400','400','yes');return false">Open Popup</a>

<a href="#" onclick="NieuwVenster(this.href,'naam','400','400','yes');return false">Open Popup</a>