well i've decided on an effect/routine

the idea has come from the program max magic
a table is presented. along with positions number one to five. there are five envelopes and four random objects e.g. calculator, watch etc. the headteacher is called out on stage, and a prediction is given to another assisstant (sp?) i explain that each item has an envelope each. i asked the head for her mobile. the items are put in the envelope, and i ask the head to mix them, when i turn my back and then i wil find it with my "magical powers"

i turn around and say i lied to her, i get her to turn around and i mix them up, so none of us no were her mobile is

. i then say i will now find your mobile, but first i need a magic wand, and then i wack out a hammer and smash one of the enevelopes. i baically do this through out and the position of her phone and the prediction are correct.
now i need a little bit of patter to go with this

perhaps a pre-story, or some one liners. anything would be of help
thanks.