Larger sketches..

Here's a pair of functions that I set up as a test, it's in HitCounter.h which is in the same directory of the main sketch.
When I open the main sketch, the HitCounter file is also opened at the same time, in another tab, but when I compile, I get an error: "Function definition does not declare parameters" Neither function takes a passed parameter, or returns one, so I don't understand the error message.

In the main sketch, I get an error saying that "HitCounter was not declared in this scope"

char Hits      = 0;

void HitCounter{
 Hits++; 
}


long Uptime    = 0;
long LastUpTime = 0;

void Update_Uptime(){
  if (millis() - LastUpTime < 1000){return;}
  Uptime++;
  LastUpTime = millis();
}

In the main application, I have this:

#include <SPI.h>
#include <Ethernet.h>
#include <OneWire.h>
#include "HitCounter.h"

(other things that are irrelevant)


// Glorious main loop with nothing in it.
void loop(){
  //pinMode(3,OUTPUT);
  //digitalWrite(3,HIGH);
  Update_Uptime();   // One function I'm trying to use 
  web();
  //digitalWrite(3,LOW);
  DS_Temp();
}

// Handles serving up pages if someone is connected
void web(){ 
  // listen for incoming clients
  EthernetClient client = server.available();
  if (client) {
    HitCounter();   // The other one I'm trying to use.
    
(more code not relevant to the issue)

}