Fail to install - Cannot read property

[Jernej]

I have followed this quick instal guide (i have added to folder toastr.css and toastr.js:

1. Link to toastr.css
2. Link to toastr.js <script src="toastr.js"></script>
3. use toastr to display a toast for info, success, warning or error
   // Display an info toast with no title
   toastr.info('Are you the 6 fingered man?')

and then I got an error:
Cannot read property 'extend' of undefined
at getOptions (toastr.js:452)
at Object.info (toastr.js:71)
at HTMLButtonElement.testClick (script.js:25)

Now I do not know how to solve this or use it (beginner here)

[Jernej]

Got it, jQuery must be added

[neilyoung]

jquery is not mentioned as dependency and I'm asking myself, why is it required?