How to call animations in JS

Hi, i would like to know how to call an animation from my Character Motor replacement script. Im pretty sure i have to make variables and call something from either an animator or a game object but the animations themselves are not on the player in any way. If i can call them from the folder thats fine but i believe i can also put them in an animation component (not sure thats why im asking). So how would i go about doing this stuff. I watched the unity mechanim tutorial and it uses C# but i need to know if JS. thanks in advance and the script is below!

 // If running is enabled, change to run speed when left shift is pressed:
         if (Input.GetKey(KeyCode.LeftShift) && enableRun == true)
         {
             speed = runSpeed;
         }
         // If crouching is enabled, change to crouch speed when "c" is pressed:
         else if (Input.GetKey("c") && enableCrouch == true)
         {
             speed = crouchSpeed;
         }
         // If nothing is pressed, use walkSpeed:
         else
         {
             speed = walkSpeed;
         }