How to get button to check cell content

Hey all,

I am trying to create a login screen which will allow some people access to one page and some, another.

I have 2 cells for USER_ID and PASSWORD. I would like it so that if the password is correct, then to continue otherwise to stay on the current page. I am thinking along the lines of...

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This (hopefully) will all be run when I click a button, which I already have set up.

TIA