Modifying Drop Down List Length

[Selacius]

I am looking for a javascript code which will modify the amount of values in a drop down list depending on the values selected in previous drop down menus. Example, I have 3 drop down lists where the maximum value is a total of 5. Now the first list will have 0 to 5, the second will have x-5, and the third will have y-5. Where x is the value selected in the first list, and y is the value from the second.