Vertex Shader Problem

[font=Consolas][font=Consolas]D3DX11CompileFromFile. Can anyone take a look at the HLSL below, and let me know if you see anything? I've been over it numerous times, and can't see what I'm doing wrong.[/font][/font]

//Sprites.vs
//--------------------------------------------------------------------------------------
// Buffers
//--------------------------------------------------------------------------------------
cbuffer OnScreen : register( b0 )
{
float2 screenSize;
}
//--------------------------------------------------------------------------------------
// Typedefs
//--------------------------------------------------------------------------------------
struct VertexInput
{
float4 Pos : POSITION;
float2 Tex : TEXCOORD0;
float2 sPos : TEXCOORD1;
float2 sSize : TEXCOORD2;
float2 tPos : TEXCOORD3;
float2 tSize : TEXCOORD4;
};
struct PixelInput
{
float4 Pos : SV_POSITION;
float2 Tex : TEXCOORD0;
};

//--------------------------------------------------------------------------------------
// Vertex Shader
//--------------------------------------------------------------------------------------
PixelInput VS( VertexInput input )
{
PixelInput output;
output.Pos = input.Pos;
output.Pos[0] = (((output.Pos[0] * output.sSize[0]) + output.sPos[0]) / screenSize[0]) - 1;
output.Pos[1] = (((output.Pos[1] * output.sSize[1]) + output.sPos[1]) / screenSize[1]) - 1;
output.Tex = input.Tex;
output.Tex[0] = ((output.Tex[0] * input.tSize[0]) + input.tPos[0]);
output.Tex[1] = ((output.Tex[1] * input.tSize[1]) + input.tPos[1]);
return output;
}