HTML - Hey Fellas,, How Shall I Flip The Coins!!

Hey there, I've been working recently on a gaming website, but i encountered a little problem ,, the thing is, am making a "Flip the Coins" game, and it's working, but what am asking is, as the owner of the website , using the same exact code, what values shall i enter that will make me always win? this is the code shown next:
"<br><br>
<form method=post action=?action=go>
Wager:<input type=text name=amount size=5>
Choice:<select name=heads>
<option value=head>Heads</option>
<option value=tail>Tails</option>
</select>
<input type=hidden name=_check value=1>
<input type=submit value=Flip!>
</form>
<br><br>"


THANKS FOR HELPING XD