function PTLamount(d) {
			
		var WrkTable=document.getElementById("PTLamountText");
		var WrkTable2=document.getElementById("PTLamountLava");
		WrkTable.style.visibility="visible";
		WrkTable2.style.visibility="visible";	
		
		var amountl = 0;
		var lava = 0;
		
	   amountl = getAmount(d);
	   lava = getlava(amountl);

      
		WrkTable.value = "You will need " + amountl + " lbs. of Glass for a 2 inch glass fill." ;
		WrkTable2.value = lava + " lbs. of Pea Size Lava Rock will give you 1 inch of lava fill.";
	
	}

	
	function getAmount(d) {
		
		var amountl=0;
		var basel =0;

        dn = d - 0;

		basel = (dn * dn * 2) / 231;
		basel = basel * .8;
		amountl = (Math.round(basel * 12));
		return amountl;
	}

	function getlava(amountl) {
		

		var lava = 0;

		amountn = amountl - 0;

		lava = Math.round((.5 * amountn) * .7);

		return lava;
	}