function chkProductDetailForm(f) {

	if (isBlank(f.quantity.value)) {
		alert("You must enter a quantity");
		f.quantity.focus();
		return false;
	}

	if (!isNumber(f.quantity.value)) {
		alert("The quantity must be numeric");
		f.quantity.focus();
		return false;
	}

	if (f.quantity.value < 1) {
	  	alert("You must enter a valid quantity.")
	  	f.quantity.focus();
	  	return false;
	}
}

function onTabClick(objId) {

	if(objId == "productFeaturesContainer") {
		showHide(objId, "block");
		showHide("customerReviewsContainer", "none");
	}
	else {
		showHide(objId, "block");
		showHide("productFeaturesContainer", "none");
	}
}


function showReviewForm() {
	showHide("reviewFormContainer", "block");
}

function onRateProductSubmit() {

	onTabClick('customerReviewsContainer')
	showHide("rateProductSubmitText", "block");
}

function onReviewProductSubmit() {

	onTabClick('customerReviewsContainer')
	showHide("reviewProductSubmitText", "block");
}