Changing an object's presence based on an amount range AND a Pull-Down Selection

Hi,

I have a form that changes various object's presence based on an amount range similar to this:

switch (true)

{

case this.rawValue >= 1 && this.rawValue <= 49999:

Subhead1.presence = "visible";

Subhead2.presence = "hidden";

break;

case this.rawValue >= 50000 && this.rawValue <= 250000:

Subhead1.presence = "hidden";

Subhead2.presence = "visible";

break;

default:

Subhead1.presence = "hidden";

Subhead2.presence = "hidden";

}

As an enhancement, I would like to add a pull-down selection field that changes the amount ranges based on the pull-down selection.

Can anyone offer any advice?

Thanks,

Eric