I am learning HLSL shading, and in my vertex shader, I have code like this:

```
VS_OUTPUT vs_main(    
    float4 inPos: POSITION, 
    float2 Txr1: TEXCOORD0 )
{
    VS_OUTPUT Output;

   Output.Position = mul( inPos, matViewProjection);
   Output.Tex1 = Txr1;

   return( Output );

}

```

It works fine. But when I was typing codes from the book, the code was like this:

```
VS_OUTPUT vs_main(    
    float4 inPos: POSITION, 
    float2 Txr1: TEXCOORD0 )
{
    VS_OUTPUT Output;

   Output.Position = mul( matViewProjection, inPos );
   Output.Tex1 = Txr1;

   return( Output );

}

```

At first I thought maybe the order does not matter. However, when I exchanged the parameters in the mul function in my code, it does not work. I don't know why. 

BTW, I am using RenderMonkey.