function radioRequired(src, image) {
	// checks if a radio button is selected
	image.style.visibility='visible';
	var itemchecked = false;
	if (src.length > 1) {
		for(var j = 0; j < src.length; j++) {

			if(src[j].checked || src[j].selected) {
				itemchecked = true;
				break;
			}
		}
	} else {
		if (src.checked || src.selected) {
			itemchecked = true;
		}
	}
	if(itemchecked)
		image.src='img/form/aan.gif';
	else
		image.src='img/form/uit.gif';

	return itemchecked;

}

function normalRequired(src, image) {
	// checks if the input field is filled.
	var returnValue = false;
	image.style.visibility='visible';
	if(src.value) {
		image.src='img/form/aan.gif';
		returnValue = true;
	} else {
		image.src='img/form/uit.gif';
		returnValue = false;
	}
	return returnValue;
}

function CheckRegion(src, image) {
	// checks if the input field is filled.
	var returnValue = false;
	image.style.visibility='visible';
	if(src != 0) {
		image.src='img/form/aan.gif';
		returnValue = true;
	} else {
		image.src='img/form/uit.gif';
		returnValue = false;
	}
	return returnValue;
}

function emailRequired(src, image){
	// Checks if an email adress is filled in correctly
	image.style.visibility='visible';
	var emailreg = /^[a-zA-Z0-9._-]+@([a-zA-Z0-9._-]+\.)+[a-zA-Z0-9.-]{2,5}$/;
		if(emailreg.test(src.value)){
			image.src='img/form/aan.gif';
			returnValue = true;
		} else {
			image.src='img/form/uit.gif';
			returnValue = false;
		}
	return returnValue;
}

function checkRequired(src, image) {
	// checks if a checkbox is selected

	var itemchecked = false;
	for(var j = 0; j < src.length; j++) {
  		if(src[j].checked) {
  			itemchecked = true;
  			break;
  		}
	}
	if (image ) {
		image.style.visibility='visible';
	}
	if(src.checked && image) {
		image.src='img/form/aan.gif';
		returnValue = true;
	} else if (image){
		image.src='img/form/uit.gif';
		returnValue = false;
	} else {
		returnValue = null;
	}

	return returnValue;

}

function comboRequired(src, image) {
	// checks if a combobox is not empty
	var itemchecked = true;
	///alert(src.length);
	//var e = src.length+' - ';
	//alert(src.options[src.selectedIndex].value)
	itemchecked = src.options[src.selectedIndex].value != ''
	//alert(e);
	if (image) {
		image.style.visibility='visible';
		if(itemchecked) {
			image.src='img/form/aan.gif';
		} else {
			image.src='img/form/uit.gif';
		}
	} else {
		if(itemchecked) {
			src.style.backgroundColor = colors.good;
		} else {
			src.style.backgroundColor = colors.wrong;
		}
	}
	return itemchecked;

}