Web Forms :: Pass Values From Parent To IFrame?

I am trying to write a simple application that will allow a user to pass a value from the parent page to a textbox in an IFrame.

Parent Page will only contain 3 controls (label, textbox, and a button). Once a user fills in the txtbox and then clicks the button I want the value that was put in the textbox to be sent to a textbox within an IFrame.

IFrame will contain a label, a textbox, and a button. Once the value is passed from the parent's textbox control to the iframe I want to also fire a button event in the iframe that will simply be:

[code]...

I am not worried about passing the value back to the parent page. My goal here is to create a testing application for my website. I want to automatically populate textbox's / radio buttons / date time pickers within an IFrame from a parent webpage. I am determining the stress on the server and testing the functional aspect of the iframe's website.