I'm watching a typescript tutorial and at one point i have to write this line of code 

```
var squareItSimpler = function(h:number, w:number) => h * w;

```

But i just can't get it to work. I keep getting the error 

```
The command "C:\Program Files (x86)\Microsoft SDKs\TypeScript\tsc.exe"  --module AMD --target ES3....exited with code 1

```

And i just don't know what to do, am i doing something wrong here ?

The funny this is that the fallowing works:

```
var squareItSimplest = (h:number, w:number) => h * w;

```

I'm using TypeScript 0.9.0.1