Spiral Blur modified to sample Custom depth buffer for soft object outlines.

SpiralBlurCustomDepth

float3 CurColor=0;
float2 NewUV = UV;
int i=0;
float StepSize = Distance / (int) DistanceSteps;
float CurDistance=0;
float2 CurOffset=0;
float SubOffset = 0;
float TwoPi = 6.283185;
float accumdist=0;

if (DistanceSteps < 1)
{
  return Texture2DSample(CustomDepthTexture,CustomDepthTextureSampler,UV);
}
else
{
  while (i < (int) DistanceSteps)
  { 
    CurDistance += StepSize; 
    for (int j = 0; j < (int) RadialSteps; j++) 
    {
      SubOffset +=1;
      CurOffset.x = cos(TwoPi*(SubOffset / RadialSteps));
      CurOffset.y = sin(TwoPi*(SubOffset / RadialSteps)); 
      NewUV.x = UV.x + CurOffset.x * CurDistance; 
      NewUV.y = UV.y + CurOffset.y * CurDistance; 
      float distpow = pow(CurDistance, KernelPower); 
      CurColor += ceil(Texture2DSample(CustomDepthTexture,CustomDepthTextureSampler,NewUV))*distpow; 
      accumdist += distpow; 
    }
    SubOffset +=RadialOffset;
    i++;
  }
  CurColor = CurColor;
  CurColor /=accumdist;
  return CurColor;
}

Is this a whole, functioning HLSL statement? why is Unreal asking me for Variable definitions when i plug this in to a custom node?