Open Dialog via JavaScript (Window size)

So I am using this javascript (pulled from MSDN) to open a Dialog via an onchange event on a field.

function openDialogProcess(dialogId, entityName, objectId)
{
var url = Xrm.Page.context.getClientUrl() +
  "/cs/dialog/rundialog.aspx?DialogId=" +
  dialogId + "&EntityName=" +
  entityName + "&ObjectId=" +
  objectId;
window.open(url);
}

Everything works great, except the problem I am having is that the Dialog opens in a new tab in the browser where I would prefer the default Dialog "popup" window. I tried playing around with the window.open parameters and was able to get it to pop out but it seems locked in to a certain size and I can't change it.

This is what I tried using window.open(url, height=200, width=150)