To open a window and to be active one always, you need to set the focus to that opened window.
Below is a sample example that can help you in your scenario.
<html>
<head>
<script>
var newWindow = null;
function openWindow()
{
if(newWindow==null)
newWindow = window.open("http://www.google.in", '_blank','height=750,width=1200, menubar=0, resizable=yes');
newWindow.focus();
}
</script>
</head>
<body>
<input type="button" value="Click" onClick="openWindow()"/>
</body>
</html>
You need to assign the window.open() to a global variable, if you do not want to open the new window always when you click on the button. At the end just set focus to that window object.
In the above example, whenever you click on button it will bring the opened(if not open) object in front.
In your example, rather passing the complete window object set, pass only the parameters to a javascript method and open window.open there in javascript method.
May be this hint can help you.