I am building a simple tool which accepts a URL, a username and a password. The URL contains one or more sets of data. After the users enters the URL, username and password. The tool then retrieves the list of data sets from the URL. The user then has to chose one of the items of the list. And then user clicks on a "Do Stuff" button where by the tool does some operation on the URL based on the item chosen by the user.
Now, I have made this is a simple window which looks like this ([ ] --> A text box)
URL [ ] UserName [ ] Password [ ]
I pre populate the URL with a default value but it is user changeable. Below this, I need to have a combo box where the user can chose from the list, but I can create this only after the URL, UserName and Password have been filled up by the user. So my idea is to have below the UserName Line
[Get List button] [Empty ComboBox]
Once the user clicks on the Get List button, I fill up the Combo Box with the Choices and then user chooses one of them.
Finally at the bottom, I will have a "Do Work" button.
My questions are
Is the Button and the Empty Combo Box a good way to do this or is there a more intuitive way?
It's not obvious that the user needs to chose something from the combo box after he clicks on the GetList button. What can I do to make this better?
Also sometimes the list may just have one item, so the Combo Box may feel strange with just one item. Should I then make the combobox invisible and replace it with a Label which shows the item name? Should I start originally (before he clicks on the Get List button) with a ComboBox or a Label or nothing at all?