var topnav1 = new Image();
topnav1.src = "images/topnav1b.gif";
var topnav2 = new Image();
topnav2.src = "images/topnav2b.gif";
var topnav3 = new Image();
topnav3.src = "images/topnav3b.gif";
var topnav4 = new Image();
topnav4.src = "images/topnav4b.gif";
var topnav5 = new Image();
topnav5.src = "images/topnav5b.gif";
var topnav6 = new Image();
topnav6.src = "images/topnav6b.gif";

function subForm (dirPage, frmName, txt) {
	var txtVal = document.forms[frmName].elements[txt].value;
	var pID = document.forms[frmName].productID.value;
	var cVal = document.forms[frmName].cook.value;
	
	if (txtVal == "") {
		alert("Please fill in a zip code to estimate shipping.");
	} else {
		window.open(dirPage + "?z=" + txtVal + "&p=" + pID + "&c=" + cVal, '', 'height=250,width=350,top=50,left=50,resizable,scrollbars');
	}

	return false;
}