04.2.md中复选框部分调用beeku中的Slice_diff报错

[Hano]

`slice:=[]string{"football","basketball","tennis"}
a:=Slice_diff(r.Form["interest"],slice)
if a == nil{
return true
}

return false`

Slice_diff中接收的参数类型是[]interface{}，而r.Form["interest"]的类型为[]string，编译时会报错