function ovr1(){
document.images["bta"].src="images/pdfon.gif"
}
function omo1(){
document.images["bta"].src="images/pdfof.gif"
}
function ovr2(){
document.images["btb"].src="images/mailon.gif"
}
function omo2(){
document.images["btb"].src="images/mailof.gif"
}
function ovr3(){
document.images["btc"].src="images/fdo.gif"
}
function omo3(){
document.images["btc"].src="images/fdm.gif"
}
function FF(img, nb)
{
    eval("document.all." + img + ".src='images/k" + nb + ".gif'");
}