function checkBrochuresTicked(checkbox)  {
		var c, i, t = 0;
		c = document.getElementById("brochure-order").brochure.length;
		for (i=0; i<c; i++)   {
			if (document.getElementById("brochure-order").brochure[i].checked == true) t = 1;
			}
		if (t == 0)   {
			alert ("You must tick at least one of the brochure boxes");
			checkbox.checked = true;
			}
		}