//this function shows/hides the moreFields div containing additional form elements
function showHide(obj){

//here we get the value of the select object
var curSel=obj.options[obj.selectedIndex].value


//if A, B, or no option selected, hide moreFields div
if(curSel=='' ){
document.getElementById('international').style.display="none";
document.getElementById('international_total').style.display="none";

document.getElementById('visa').style.display="none";
document.getElementById('visa_total').style.display="none";
document.getElementById('visa_percent').style.display="none";

document.getElementById('amex').style.display="none";
document.getElementById('amex_total').style.display="none";
document.getElementById('amex_percent').style.display="none";

}

else if ((curSel=='Visa' || curSel=='MasterCard' || curSel=='Discover') && curSel=="United States"){

//otherwise show moreFields div
document.getElementById('international').style.display="none";
document.getElementById('international_total').style.display="none";

document.getElementById('visa').style.display="block";
document.getElementById('visa_total').style.display="block";
document.getElementById('visa_percent').style.display="block";

document.getElementById('amex').style.display="none";
document.getElementById('amex_total').style.display="none";
document.getElementById('amex_percent').style.display="none";
}

else if (curSel=='AmericanExpress' && curSel=="United States"){

//otherwise show moreFields div
document.getElementById('international').style.display="none";
document.getElementById('international_total').style.display="none";

document.getElementById('visa').style.display="none";
document.getElementById('visa_total').style.display="none";
document.getElementById('visa_percent').style.display="none";

document.getElementById('amex').style.display="block";
document.getElementById('amex_total').style.display="block";
document.getElementById('amex_percent').style.display="block";
}
else if (curSel!='United States'){

//otherwise show moreFields div
document.getElementById('international').style.display="none";
document.getElementById('international_total').style.display="none";

document.getElementById('visa').style.display="none";
document.getElementById('visa_total').style.display="none";
document.getElementById('visa_percent').style.display="none";

document.getElementById('amex').style.display="block";
document.getElementById('amex_total').style.display="block";
document.getElementById('amex_percent').style.display="block";
}

}