[RESOLVED] Why do i get this warning?

[cc2^^]

I have created a DLL in C++ that contains a function which a program made in VB6 will use.
But i get the Overflow error when running the app.
I know for sure it is the function in the DLL that causes this.

Here is the function:

void __stdcall DLL_EXPORT CalculateGravity(double *X1,double *Y1,double *X2,double *Y2,double *FX1,double *FY1,double *FX2,double *FY2,double *W1,double *W2,double MaxAttraction,double MaxMovement,boolean AffectOnlyOne)
{
double dx;
double dy;
double d1;
double d2;
double F1;
double F2;
double TempX;
double TempY;
double D;

if (AffectOnlyOne)  //Only Particle 1 Moves
{

   dx == *X1 - *X2;
   dy == *Y1 - *Y2;
   d1 == (dx * dx) + (dy * dy);
   if (d1 == 0) {d1 = 0.00001;}
   F1 == *W2 / (d1 * sqrt(d1));
   if (F1 > MaxAttraction) {F1 == MaxAttraction;}
   TempX == *FX1 - (F1 * dx);
   TempY == *FY1 - (F1 * dy);
   D == sqrt((abs(TempX) * abs(TempX)) + (abs(TempY) * abs(TempY))); //When i remove this line of code here, the Overflow error stops occuring.
   if (D > MaxMovement) {
   D == D / MaxMovement;
   TempX == TempX / D;
   TempY == TempY / D;
   }
   *FX1 = TempX;
   *FY1 = TempY;

}
else  //Both Particle 1 and Particle 2 Moves
{
//not done with this part yet

}
}

And it gets called from the VB6 app like this:

'Simulating the particles around the galaxy
For i = 1 To UBound(P) - 1
   CalculateGravity P(i).X(CurrentFrame), P(i).Y(CurrentFrame), P(0).X(CurrentFrame), P(0).Y(CurrentFrame), P(i).fx, P(i).fy, P(0).fx, P(0).fy, P(i).W, P(0).W, MaxAttraction, MaxMovement, True
   ReDim Preserve P(i).X(MaxProcessFrame + 1)
   ReDim Preserve P(i).Y(MaxProcessFrame + 1)
   P(i).X(CurrentFrame + 1) = P(i).X(CurrentFrame) + P(i).fx
   P(i).Y(CurrentFrame + 1) = P(i).Y(CurrentFrame) + P(i).fy
Next

Basically what this function does is it calculates a bunch of stuff and then overwrites the result on two variables (FX1 and FY1). Those two variables is stored on the VB6 app that calls the function.

Also when i compile the DLL i get alot of warnings saying "Statement has no effect" on almost every line of code.

I'm new to C++, so excuse me if i'm missing something obvious here.

If anyone knows why i get those warnings and the Overflow error please let me know. Thanks.