public override void OnDoubleClick( Mobile from )
{
if ( !IsChildOf( from.Backpack ) )
{
from.SendLocalizedMessage( 1042001 ); // That must be in your pack for you to use it.
}
else
{
from.BeginTarget( 2, false, TargetFlags.None, new TargetCallback( OnTarget ) );
from.SendMessage( "What do you wish to use the gem on?" );
}
}