function validate()
{
	var message = "";

    message += ValidateEmpty(commentTextElementName, "Please enter your comment.\n");
    
	if(message.length > 0)
	{
		message = "The following errors occurred: \n\n" + message;
		alert(message);
		
		if(firstInvalidElement != null)
		{
			firstInvalidElement.focus();
			firstInvalidElement = null;
		}

		return false;
	}
	else
	{
		return true;
	}
}
var firstInvalidElement;

function ValidateEmpty(elementId, messageOnError)
{
	var element = document.getElementById(elementId);
	if(element.value == "")
	{
		if(firstInvalidElement == null)
		{
			firstInvalidElement = element;
		}
			
		return messageOnError;
	}
	else
	{
		return "";
	}
}