function addLoadEvent(func)
{
	var oldonload = window.onload;
	if (typeof window.onload != 'function')
	{
		window.onload = func;
	}
	else
	{
		window.onload = function()
		{
			oldonload();
			func();
		}
	}
}



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("Gelieve alle verplichte velden in te vullen.");
				element.focus();
				return false;
			}
		}
		if (element.className.indexOf("email") != -1)
		{
			if (!isEmail(element))
			{
				alert("Gelieve een geldig e-mailadres in te vullen.");
				element.focus();
				return false;
			}
		}
	}
	return true;
}



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 prepareForms()
{
	for (var i=0; i<document.forms.length; i++)
	{
		var thisform = document.forms[i];
		thisform.onsubmit = function()
		{
			return validateForm(this);
		}
	}
}



addLoadEvent(prepareForms);