It looks like you're trying to combine pieces of HTML and JavaScript, but I think I would go with something a bit more straightforward:
var text URL =URLRoot() & "db/" & Dbid() & "?a=er&rid=" & ToText([Record ID#]);"<a class='Vibrant Success' &href=" & $url & " target='_blank'>Edit</a>"
This will simply open the URL in a new window, though it won't limit the size of the window.
------------------------------
Blake Harrison
bharrison@datablender.io
DataBlender - Quick Base Solution Provider
Atlanta GA
404.800.1702 /
http://datablender.io/------------------------------