function validatePrompt (veld, PromptStr) {
		alert(PromptStr);
		veld.focus();
	}
	function testnotemptyorspace (field, description) {
		text = "Het veld '" + description + "' is een verplicht veld.";
	    if (field.value == "" || field.value == " ") {
	        validatePrompt (field, text);
	        field.focus();
	        return (false);
	    }
	    return (true);
	}
	function testemail (field, description, emptyok) {
		if (!emptyok) {
			text = "Het veld '" + description + "' moet ingevuld worden en mag alleen een geldig e-mailadres bevatten.";
		}
		else {
			text = "In het veld '" + description + "' staat een ongeldig e-mail adres."
		}
		if (field.value != "" && field.value != " ") {
			var i = 1;
			var sLength = field.value.length;
			while ((i < sLength) && (field.value.charAt(i) != "@")) {
			    i++
			}

			if ((i >= sLength) || (field.value.charAt(i) != "@")) {
			    validatePrompt (field, text);
			    return (false);
			}
			else i += 2;

			// look for .
			while ((i < sLength) && (field.value.charAt(i) != ".")) {
			    i++
			}

			// there must be at least one character after the .
			if ((i >= sLength - 1) || (field.value.charAt(i) != ".")) {
			    validatePrompt (field, text);
			    return (false);
			}
		}
		else {
			if (emptyok == false) {
			    validatePrompt (field, text);
			    return (false);
			}
		}
		return (true);
	}
	function SubmitContent() {
		if (!testnotemptyorspace(document.form.naam, 'Naam')) return;
		if (!testnotemptyorspace(document.form.email, 'E-mail')) return;
		if (!testemail(document.form.email, 'E-mail')) return;
		if (!testnotemptyorspace(document.form.antwoord, 'Antwoord')) return;
		if (document.form.antwoord.value.length > 5){
			alert("Het antwoord is te lang!");
			return false;
		}
		document.form.submit();
		return;
	}