"Any cross sectional slice of a certain solid in a plane perpendicular to the x-axis is a square with side AB, with A lying on the curve $\displaystyle y^2 = 4x$ and B on the curve $\displaystyle x^2 = 4y$. Find the volume of the solid lying between the points of intersection of these two curves."

I'm not sure if I'm going in the right direction, but so far I've put the curves in terms of y, leaving me with $\displaystyle y = 2\sqrt{x}$ and $\displaystyle y = \frac{x^2}{4}$. After graphing, I also know that the limits of integration will be from 0 to 4 since the points of intersection are at (0, 0) and (4, 4). From here on, I'm completely lost.

Thanks