How do you make the stage change once the sprite hits the edge?

How would you make the stage of the project change once the sprite hits the edge?

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Thank you fro your answer! However, the "switch to costume" block only gives me sprite costume options. How do I fix this?

Click on the stage icon in the sprite corral Google%20Chrome001. Drag a SET BACKGROUND block onto the icon of the application panel; then switch to that panel and put the block where desired.

Or this.
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edit: or this
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