function checkForm(whichform) {
	var error = "";
	for (var i=0; i < whichform.elements.length; i++) {
		var element = whichform.elements[i];
		if( (element.type == 'text') && (element.className.indexOf("required") != -1) ) {
			if (!isFilled(element)) {
				element.style.backgroundColor = "#FFA3B8";
				error += element.id + " is a required field.\n";
			} else {
				element.style.backgroundColor = "";
			}
			if (element.className.indexOf("email") != -1) {
				if(!simpleIsEmail(element)) {
					error += "Please provide a valid email address\n";
					element.style.backgroundColor = "#FFA3B8";
				} else {
					element.style.backgroundColor = "";
				}
			}
		}
	}
	if (error == "") {
		return true;
	} else {
		alert(error);
		return false;
	}
}

function isFilled(aField){
	if (aField.value.length < 1){
		return false;
	} else {
		return true;
	}
}

function simpleIsEmail(email) {
	if (email.value.indexOf("@") == -1 || email.value.indexOf(".") == -1){
		return false;
	} else {
		return true;
	}
}

function prepareForm() {
	for (var i=0; i<document.forms.length; i++) {
		var thisForm = document.forms[i];
		thisForm.onsubmit = function() {
			return checkForm(this);
		}
	}
}