function isFilled(field) {
	if (field.value.length<1 || field.value == field.defaultValue) {
   	return false;
	
  }	else {
	return true;
  }
}

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

function validateForm (whichform) {
	for (var i=0; i<whichform.elements.length; i++) {
		var element = whichform.elements [i];
		if (element.className.indexOf("required") != -1) {
			if (!isFilled(element)) {
				alert("Please fill in the "+element.name+" field.");
				return false;
			} 
			}
		if (element.className.indexOf("email") != -1) {
			if(!isEmail(element)) {
			   alert ("The "+element.name+" field must be a valid email address.");
			   	return false;
				}
			}
		}
		return true;
	}