MVC-pop up windows

I need to create pop up windows in mvc(not new tab in browser). Does anyone know how to do this?

One possibility is to use jquery ui dialog.

EDIT

The idea would be to have an ajax action that returns a partial view. The result of that action (html) is placed inside the container of the popup and on the success handler of the ajax call you open the popup. Here is some sample code:

@Ajax.ActionLink("Open popup", "SomeAction", new AjaxOptions { HttpMethod = "GET", UpdateTargetId = "result", InsertionMode = InsertionMode.Replace, OnSuccess="openPopup" })<br />

<div id="result" style="display:none;"></div>

<script type="text/javascript">
$(document).ready(function() {
    $("#result").dialog({
        autoOpen: false,
        title: 'Title',
        width: 500,
        height: 'auto',
        modal: true
    });
});
function openPopup() {
    $("#result").dialog("open");
}
</script>

Then you have to add the action in the controller that returns the partial view

 [HttpGet]
 public PartialViewResult SomeAction()
 {
      return PartialView();
 }

Place whatever you need in the partial view, you may also include parameters in the action, etc.

Good luck!

Most obvious way is using one of js frameworks. Personally I prefere jQuery UI dialog control.
Please check http://jqueryui.com/demos/dialog/ for detailed information about it.
Also you may check ASP.NET MVC modal dialog/popup best practice (it's question similar to yours)

Of course if you need some simple popup you always may use alert('Im popup');

Update according your latest request
To open some url in new window you may use next javascript:

function OpenDialog() {
window.open("some url", "DialogName", "height=200,width=200,modal=yes,alwaysRaised=yes");
}

But result really depends on browser. Most of them open this modal window not in new tab but in new browser instance.
This topic might help you aswell:
JavaScript open in a new window, not tab