SOLVED: How to make a non-selectable block?

[Flayr]

I have been trying for a while and cannot find a good way to do this. How do I make a block that your cursor just goes through allowing you to destroy the block behind it and not destroy it (just like how you cant click on water, but can still build underwater).

 

Thanks in advance.

[Draco18s]

    public MovingObjectPosition collisionRayTrace(World par1World, int par2, int par3, int par4, Vec3 par5Vec3, Vec3 par6Vec3)
    {
    	return null;
    }