static class not functioning

So, I got his code:

    #pragma strict
     public class Charge {
     
     public static var charge_time : int = 2;
     
     function Update()
     {
     print (charge_time);
     if (Input.GetKey(KeyCode.Space)){
     charge_time --;
     }
     
     
     if (Input.GetKeyUp(KeyCode.Space)) {
     charge_time = 2;}
     }
     }
 
 

The problem is: I tried this thing, and it seems that the variabe "charge_time" didn't change its value, this thing didn't ever print anything at all,

I tried the print in other scripts, the script prints it successfully, but the value appeared to be remain unchanged. I think the problem is that

     if (Input.GetKey(KeyCode.Space)){
         charge_time --;}

is not functioning nor functioning in a loop.

I wish for another reply for the noob standing here.