Помогите найти ошибку:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<input id="a" size="40">
<input id="b" size="40">
<input id="c" size="40">
<script>
function dc_go() {
var a = document.getElementById("b")
var b = document.getElementById("b")
var c = document.getElementById("c")
var d = b * b - 4 * a * c;
if (d < 0) {
alert( "Корней нет!" )
} else {
var ask1 = (-b + Math.sqrt(d)) / (2 * a);
var ask2 = (-b - Math.sqrt(d)) / (2 * a);
alert(d)
if (d == 0) {
alert(ask1);
} else {
alert(ask1);
alert(ask2)
}
}
}
</script>
<input type="button" onclick="dc_go" value="Show!">
</body>
</html>
</script>
</body>
</html>