Add a button to TinyMCE with popup dialog box?

I need to add a button to my tinymce editor for my theme that will insert a shortcode. The shortcode has 5 options, and I know that the person that I am building the theme for won’t remember them all. So I want to be able to have a dialog box popup (similar to the link button dialog) that’ll allow her to fill out a form that will auto insert the full shortcode. How Do I do this?


(function() {
tinymce.create('tinymce.plugins.BrettsYouTube', {
init : function(ed, url) {
ed.addButton('brettsyoutube', {
title : 'brettsyoutube.youtube',
image : url+'/youtube.png',
onclick : function() {
idPattern = /(?:(?:[^v]+)+v.)?([^&=]{11})(?=&|$)/;

//I want to replace this with the dialog
var vidId = prompt("YouTube Video", "Enter the id or url for your video");

var m = idPattern.exec(vidId);
if (m != null && m != 'undefined')
ed.execCommand('mceInsertContent', false, '[youtube id="'+m[1]+'"]');
}
});
},
createControl : function(n, cm) {
return null;
},
getInfo : function() {
return {
longname : "Brett's YouTube Shortcode",
author : 'Brett Terpstra',
authorurl : 'http://brettterpstra.com/',
infourl : 'http://brettterpstra.com/',
version : "1.0"
};
}
});
tinymce.PluginManager.add('brettsyoutube', tinymce.plugins.BrettsYouTube);
})();