var freeItemCount=0 
var maxFreeItems=3 

function setItems(item)
{ 
  if(item.checked)
  {freeItemCount=freeItemCount+1}

else
 {freeItemCount=freeItemCount-1} 

if (freeItemCount>maxFreeItems)
  {item.checked=false 
  freeItemCount=freeItemCount-1 
  alert('You may only choose '+maxFreeItems+' Brochures. Please choose the '+maxFreeItems+' items you want us to include with this order ') 
  } 
}