Forgot Username Feature

[mattyastill]

I am having a little bit of trouble doing this feature. Basically i have a system where the user will log in using their desired username and password. i want a macro which will have a box appear asking the user for their email. Once it has got the email it will go the "Userdetails" sheet and find the information and then email it to them. Would anyone be able to tell me how i am to go about getting a box which i can input data into and then use the data in the macro.

Thanks