Drag to Aim, Release to shoot?

I am creating a 'clone' of the game Soccer Stars and I want to have my mouse drag on the disc and when it releases, to add a force proportional to the distance the mouse traveled to the disc. Does anyone have some example code on how to do this? I'm a visual learner so just saying you need this or this doesn't help me too much.

 

Noones going to give you scripts, but this MIGHT help:
Vector3 force = new Vector3();

Update

if mousebutton is held down

force = (mouse.position in world coords) - position of gameObject you want to launch
​

if mousebutton is released and force != Vector3.zero

apply force to gameObject

You may need to set the force.y to 0.​

 

That helps. I'm not asking for the entire script, I'm just not sure how to set it up so little examples like this help me.

 

I forgot to add the force = Vector3.Zero after applying force