How am I suppose to hide a Dialog after the function is complete?

I've been trying to figure this out for a while now. I tried switching It's Parent, but that doesn't work apparently either. Here's an example of what's happening:

http://dw4.convertfiles.com/files/0158373001423174479/video_2015-02-05_171045.avi It's a gif site, not a download. and here's the code:

script.Parent.DialogChoiceSelected:connect(function(Player, Choice)
    if Choice.Name=="yes" then
        wait(1)
        for t=0,1,0.01 do
            script.Parent.Parent.face.Transparency=t
            for i,v in pairs(script.Parent.Parent.Parent:getChildren()) do
            --stuff
        end --end "t"
-- I COULD REMOVE THE DIALOG HERE. but that's not what I want...
    end --end Choice=="yes"
    script.Parent["purpose change"].Disabled=false
end)

Help would be appreciated lads.