求助大神，找出错误之处
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>prompt</title>
<script>
function rec()
{
var score;
score=prompt("请输入你的成绩：");
if(socre>=90)
{
document.write("你很棒");
}
else if(score>=75)
{
document.write("不错呦！");
}
else if(score>=60)
{
document.write("加油！");
}
else
{
document.write("你很差");
}
}
rec();
</script>
</head>
<body>
<input name="button" type="button" onclick="rec()" value="点击我，对成绩作评价">
</body>
</html>
