You can do this way. For example I am opening http:www.google.com with two parameters in the query string.
function test()
{
var value1 =100;
var value2 =200;
window.open("http://www.google.com?param1=" + value1 + "¶m2=" + value2, "", "dialogWidth:875px;dialogHeight:600px");
}
Ok try this way ...
function Test() {
var value1 = 100;
var value2 = 200;
var value3 = 300;
window.open('<%=Url.Action("Index?param1=") %> ' + value1 + '¶m2=' + value2 + '¶m3=' + value3, "", "dialogWidth:875px;dialogHeight:600px");
}