I am wondering how you can make a dropdown field where there are two drop down fields, and once you select one of them the other option change to match the user input.  For example, if the first dropdown lookup menu had options A, B, C, and D then if the user selected option B, in the next dropdown lookup menu it would list options Z, Y, T, and F but if you were to select A from the first dropdown lookup, then the second dropdown lookup menu would change to select X, M, L, and K.  I really need some help on this.  Hope that isn't too confusing.

Thanks,

Michael McNeill