A problem about Effects

I add a Subtract Effect to a square sprite

<img src="https://r6mzha.bay.livefilestore.com/y1pycrDw6yDhFmbc9a7UsDHkX4UQ96BYzGoE9VD0xkwJXrXUKAYP2VrC2jBgAK2ZsKKUMPt_of5yV2qCEse2nW_16LZEybNtgpD/sd.jpg" border="0" />

I will be like this:

<img src="https://r6mzha.bay.livefilestore.com/y1pLAB18Ps5iC3GHSc2QYiYtxomrbxA5QIpCDXdObXuZagggUrJQlz43gKK66V_hMd20kPl17rBIWhRKXEBdn4A3VQuI_TySkgf/sdf.jpg" border="0" />

But I want it to be like this:

<img src="https://r6mzha.bay.livefilestore.com/y1pcbZaSJM21CeiB8PxV873CkI2xrhF1ujxU1O2tStRxW90-uU5QSUFqaH0hKdhDlNupvZPOgP9euBh1g8_r-EiGG35iA4CmkYK/sdff.jpg" border="0" />

In other words, I want the Effect only work in it's layer(can not affect the Objects in other layer), What I have to do?

PS: I'm not from a contry which speak English, so please forgive me if I say something wrong. =w=

subtract effect won't do it. look into sprite masking.

Could you tell me how to use it?

You can try set opacity 0 or make it invisible.

Could you tell me how to use it?

It's cheap trick, create a blue square sprite with same color to background

Try giving it the destination-out blend mode, putting it on the same layer as the yellow object with the blue object on a different layer underneath, then marking the layer with the yellow object to 'Force own texture'.

Thanks, your answer is what I want