How to clear text field on focus of text field

Question

I want to clear the text field when the user clicks on that

Answer 1

Unless you are doing something specific where you only want to clear onclick, I would suggest (as others have noted) to use the onfocus actions instead. This way if someone is using tab to navigate it will also clear the default text.

You can also use onblur to check if it's empty to bring it back: