How to create a sprint button?

Hi im new to Unity and am creating a FPS. I need a sprint button but dont know how to create one. If someone would be so kind to leave a script for a sprint button and instrutions on applying it to the left shift key, i would be greatefull.

P.S. If the sprint is limited and needs rechargin after a certan amount of use it would be even better.

Thanks in advance.

Take a look at this question - it shows how to run and crouch with the standard First Person Controller.

Thank you for that tag, helped alot.