How to make a editable pdf with explaining text that disappears when you type?

I want to make a pdf file in which it is possible to fill out some text fields. In these text fields I want to write some text explaining what you should type in the fields (for example: "write your name here"). How do I do this?

When I start typing in the fields the text explaining what you should write does not disappear as I would like it to.

Can anyone help me?