Creating/Saving Templates

I've created a Quotation Template for my company and would like to save it as
a template so that when someone uses the document and fills it out it prompts
them to "Save As" rather than "Save". This way the original blank document
is preserved. However, when I save it as a Template it doesn't prevent
another user from saving over it. Does anyone know how I can lock the "Save"
function? So that only the "Save As" is available?