x.js

/* This is a template command. */
CmdUtils.CreateCommand({
  names: ["new tab","new-tab"],
  icon: "http://www.mozilla.com/favicon.ico",
  description: "Opens the passed URL in a new tab",
  help: "open-in-new-tab http://www.mozilla.com",
  author: {name: "Scott Hosfeld", email: "junk4hos+ubiquity@gmail.com"},
  license: "GPL",
  homepage: "",
  arguments: [{role: 'object', nountype: noun_arb_text, label:"url"}],

  _getUrl: function(args){
    var url = args.object.text;
    url = url.replace(/\s+/g, "");

    var proto = /^(http|https|ftp)\:///

    if (!proto.test(url)){url='http://'+url;}

	var urlRegx = /^((http|https|ftp)\:\/\/).*(\.[\w]{2,6})((\.[\w]{2,6})|(\/[a-zA-Z0-9\-]*)*)$/
	
	var retUrl = {};
	retUrl.url = url;
	retUrl.goodUrl = urlRegx.test(url);
	
return retUrl;
},

  preview: function preview(pblock, args) {
     var urlObj = this._getUrl(args);

	 if (urlObj.goodUrl){
    pblock.innerHTML = _("Open <b>${url}</b> in a new tab",urlObj);
	}else{
	pblock.innerHTML = _("${url} is not a valid URL", urlObj);
	}
  },

  execute: function(args) {
	var urlObj = this._getUrl(args);
	
	if (urlObj.goodUrl){
		Utils.openUrlInBrowser(urlObj.url);
	}else{
		displayMessage(_("${url} is not a valid URL", urlObj ));
	}

  }
  
});