html and javascript. checkbox to textbox?

[Nonyabusiness]

So i have to use information from a checkbox and put it in a textbox when a submit button is pressed. And i don't know what function to use.

So here's my checkbox.
<form action="" name="sport">
<p><strong>What is your favorite sport?</strong></p>
Basketball:
<input type="checkbox" name="check" value="Basketball" onclick="Basketball" />
<br />
Football:
<input type="checkbox" name="check" value="Football" onclick="Football"/>
<br />
Hockey:
<input type="checkbox" name="check" value="Hockey" onclick="Hockey" />
<br />
Soccer:
<input type="checkbox" name="check" value="Soccer" onclick="Soccer" />

</form>

And here's the textbox where i need to transfer the information of the checked boxes to.
<form action="" name="activity">
<strong>Do you want something to do today?</strong>
<input type="submit" value="Yes" onclick=""/>
<input type="text" name="answer" />
</form>


How do i do this?