new to JavaScript, I can't get this to work

[Computer_Hopeless]

I'm learning JavaScript (with the aid of online tutorials) and can't figure out where I messed up. This is what I have and where the problem seems to be:

<script type="text/javascript">
var apples = 10;
alert('There are currently ' + apples + ' apples!');

var toss = prompt('How many apples would you like to throw at the doctor?', '0');

var thrown = parseInt(toss);
if(thrown > apples){
   alert('Sorry, but there are not that many apples.  You can not throw ' + thrown + ' apples!');
} else { if(apples - thrown = 1){
      alert('Now there is only one apple left to throw!');
   } else {apples -= thrown;
      alert('Now there are only ' + apples + ' apple(s) left to throw!');
      }
}
</script>

Is there some weird rule about having if/else statements within other if/else statements? Or did I mess up in my ignorance elsewhere?

Any help would be greatly appreciated.

[michaewlewis]

you're missing an equals when checking if there's only one apple left
change to this: if(apples-thrown==1)

[Computer_Hopeless]

Thanks a million. I had no clue I had to use a double =, that'll be quite helpful not only with this script but with many others in the future. Thank you again.