Calc() Issue Not Going Over 2??

I have a javascript calculator that when you update a users level you click calculate and it updates there skill needed to reach the next level my problem is it only calculates as high as the number 2:

echo "<script langauage="javascript">
function calc() {
a = document.battle.newlevel.value;
b = 150;
c = document.battle.newskillneed.value;
answer = eval(a*a*b);
if(c>answer) {
document.battle.newskillneed.value = answer;
}
max.innerHTML = answer;
}
</script>";

Example: Level 2*(150 * Level 2) = 600 works fine but
Level 3*(150 * Level 3) = nothing why won't it work any higher its like there is a cap on how high it will go...

Also if I enter level 1 it comes up with 150 but if i put in level2 and press calculate it won't do anything but if i start out at level2 it works and then i move down to level 1 it works why won't it work moving up in numbers??