function mastheadHigh() {
    document.images["masthead_sm"].src = "images/bdp_masthead_sm2_h.jpg";
}

function mastheadLow() {
    document.images["masthead_sm"].src = "images/bdp_masthead_sm2.jpg";
}

function toothHigh() {
    document.images["plaxcan"].src="images/022_01.jpg";
}

function toothLow() {
    document.images["plaxcan"].src="images/022_01-over.jpg";
}