I am trying to understand scoping in JS.Here i have an example which has a variable in global scope called `check`.It has a truthy value i mean `1`.Then inside a function called `main` which `doesn't have a variable called check` but has an `if statement` which checks whether there is a check variable or not ,upon which it reassign another value to check variable.Then prints it out.if i use 

```
if(check){}

```

it prints undefined.*Here i have some questions*:

**1.** check variable is declared in global scope.It means it has access everywhere.Then even if the `IF statement` fails it should print the globally assigned value which is 1 instead of undefined.Why it prints undefined instead of 1??

**2.** main function scope doesn't have a check variable.When if fails to find check inside main function's scope ,why it doesn't look for it in global scope??

```js
  (function(){
        var check=1;
        function main(){
      if(check){
               var check=10;
         }
   document.write(check);
   }
  main();
    })();
```