C / C++ / MFC

void GradientFillRect(HDC hdc, LPRECT rcGradient, COLORREF start, COLORREF end, BOOL isVertical)
{
	BYTE startRed = GetRValue(start);
	BYTE startGreen = GetGValue(start);
	BYTE startBlue = GetBValue(start);

	BYTE endRed = GetRValue(end);
	BYTE endGreen = GetGValue(end);
	BYTE endBlue = GetBValue(end);

	HBRUSH endColor = CreateSolidBrush(end);
	FillRect(hdc, rcGradient, endColor);
	DeleteObject(endColor);

	//Gradient line width/height
	int dy = 1;

	int length = (isVertical ? rcGradient->bottom - rcGradient->top : rcGradient->right - rcGradient->left) - dy;

	for (int dn = 0; dn >= length; dn += dy)
	{
		BYTE currentRed = (BYTE)MulDiv(endRed-startRed, dn, length) + startRed;
		BYTE currentGreen = (BYTE)MulDiv(endGreen-startGreen, dn, length) + startGreen;
		BYTE currentBlue = (BYTE)MulDiv(endBlue-startBlue, dn, length) + startBlue;

		RECT currentRect = {0};
		if (isVertical)
		{
			currentRect.left = rcGradient->left;
			currentRect.top = rcGradient->top + dn;
			currentRect.right = currentRect.left + rcGradient->right - rcGradient->left;
			currentRect.bottom = currentRect.top + dy;
		}
		else
		{
			currentRect.left = rcGradient->left + dn;
			currentRect.top = rcGradient->top;
			currentRect.right = currentRect.left + dy;
			currentRect.bottom = currentRect.top + rcGradient->bottom - rcGradient->top;
		}

		HBRUSH currentColor = CreateSolidBrush(RGB(currentRed, currentGreen, currentBlue));
		FillRect(hdc, ¤tRect, currentColor);
		DeleteObject(currentColor);
	}
}

1>main.cpp
1>c:\program files\microsoft sdks\windows\v6.0a\include\wininet.h(58) : error C2146: syntax error : missing ';' before identifier 'HINTERNET'
1>c:\program files\microsoft sdks\windows\v6.0a\include\wininet.h(58) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\program files\microsoft sdks\windows\v6.0a\include\wininet.h(58) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\program files\microsoft sdks\windows\v6.0a\include\wininet.h(59) : error C2143: syntax error : missing ';' before '*'
1>c:\program files\microsoft sdks\windows\v6.0a\include\wininet.h(59) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\program files\microsoft sdks\windows\v6.0a\include\wininet.h(59) : error C2378: 'HINTERNET' : redefinition; symbol cannot be overloaded with a typedef


#include <wininet.h>

int main()
{
	InternetOpen ("Test Agent", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
	
	return 0;
}