Fill-In Forms

I need to create a fill-in form which will automatically prompt the user to enter information when the form is opened.
I have created fill-in fields as required on the form. I can then select the document (Ctrl+A) and press F9 and Word will take me through the prompts. But I really need this form to automatically prompt the user to enter information when the form is opened. Does anyone know how this can be done? I have tried various ways but still can not get it to work. Would appreciate any ones help.