var MIN_BOOK_PRICE = 99;

function onServiceChange() 
	{var service = document.getElementById( "Service" );
	if ( -1 == service.selectedIndex )
	return;var sService = service.options[ service.selectedIndex ].value;
	if ( -1 == sService.indexOf( "E" ) )
	return;var sPrice = sService.substr( sService.indexOf( "E" ) + 1 );
	var book = document.getElementById( "Free_Book" );
	if ( MIN_BOOK_PRICE > sPrice ) {book.selectedIndex = 0;book.disabled = true;}
	else {book.disabled = false;
}
document.getElementById( "Messenger_SMS" ).disabled = ( -1 == sService.indexOf( "Plus" ) );
document.getElementById( "ID_SMS" ).disabled = ( -1 == sService.indexOf( "Plus" ) );
}

window.onload = function() {
	onServiceChange();
}

function verifyIP (IPvalue) {
errorString = "";
theName = "IPaddress";

var ipPattern = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/;
var ipArray = IPvalue.match(ipPattern);

if (IPvalue == "0.0.0.0")
errorString = errorString + theName + ': '+IPvalue+' is a special IP address and cannot be used here.';
else if (IPvalue == "255.255.255.255")
errorString = errorString + theName + ': '+IPvalue+' is a special IP address and cannot be used here.';
if (ipArray == null)
errorString = errorString + theName + ': '+IPvalue+' is not a valid IP address.';
else {
for (i = 0; i < 4; i++) {
thisSegment = ipArray[i];
if (thisSegment > 255) {
errorString = errorString + theName + ': '+IPvalue+' is not a valid IP address.';
i = 4;
}
if ((i == 0) && (thisSegment > 255)) {
errorString = errorString + theName + ': '+IPvalue+' is a special IP address and cannot be used here.';
i = 4;
      }
   }
}
// extensionLength = 3;
if (!errorString == "")
alert (errorString);
}