javascript window.open not working in IE

[jlbantang]

Hi, Im using a custom function to open window most of the time it works in IE,FF and CHROME but when I pass the value

onclick="popupwindow01('supplier.aspx?src=rpt&tar=costcentre','Page Title',400,500);"

in IE debugger local window it shows

url 
value="supplier.aspx?src=rpt&tar=costcentre"
type=String

title
value="Page Title"

w=400
h=500

function popupwindow01(url, title, w, h) {
  var left = (screen.width/2)-(w/2);
  var top = (screen.height/3)-(h/2);  
   window.open(url, title, 'toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=no, resizable=no, copyhistory=no, width='+w+', height='+h+', top='+top+', left='+left).focus();
}

Thanks in advance.