simple wordpress plugin

I need a very basic wordpress "dialogoo" plugin: 1) in the installation panel of the plugin, the user needs to enter his id number (ex: 2509) It also provide a link to a website to create this id if the user has not got it ex: [login to view URL] 2) then the user will put [dialogoochat 2509] into hist page, it will insert a javascript inside the html ex: <javascript src="[login to view URL]"></script>