// These functions ensure consistency between print colour options and ink colour
// GT 17/07/08

function print_colour()
  {
  // if B&W printing is selected then automatically select black ink colour  
  if ( document.cart_quantity.ColourOption.selectedIndex == 0 )
     { document.cart_quantity.elements["id[15]"].selectedIndex = 0;}
  }

function ink_colour()
  {
  // if an ink colour other than black is selected then also switch on full colour printing
  if ( document.cart_quantity.elements["id[15]"].selectedIndex > 0 )
     {  document.cart_quantity.ColourOption.selectedIndex = 1; }
  update_prices("",0);
  }