Just do something like this then:

```C++
	void SetInternalResolution(int res = -1) {
		if (res >= 0)
			g_Config.iInternalResolution = res;
		else {
			if (g_Config.iInternalResolution < 11)
				++g_Config.iInternalResolution;
			else
				g_Config.iInternalResolution = 0;
		}
			
	}
```

And then for resolution dummy:

```C++
				case ID_OPTIONS_RESOLUTIONDUMMY:
					{
						SetInternalResolution();
						ResizeDisplay(true);
						break;
					}
```

This way you don't have to muck around with having a separate variable.