js6----for循环计算通关分数

function jisuan()
{
var guan = document.getElementById("guan").value;
var text = document.getElementById("text");
if(guan!="")
{
guan=parseFloat(guan);
if(guan%1==0)
{
if(guan>0&&guan<=50)
{
var sum = 0;
for(var i=1;i<=guan;i++)
{
if(guan<=20)
{
sum+=i;
}
else if(guan<=30)
{
sum+=10;
}
else if(guan<=40)
{
sum+=20;
}
else if(guan<50)
{
sum+=30;
}
else
{
sum+=100;
}
}
text.value="分数:"+sum;
}
else
{
text.value="关卡输入不对";
}
}
else
{
text.value="必须是整数";
}
}
else
{0.

text.value="不能为空";
}
}
</script>