function getRadioValue (radioButtonOrGroup) {
  var value = null;
  if (radioButtonOrGroup.length) { // group 
    for (var b = 0; b < radioButtonOrGroup.length; b++)
      if (radioButtonOrGroup[b].checked)
        value = radioButtonOrGroup[b].value;
  }
  else if (radioButtonOrGroup.checked)
    value = radioButtonOrGroup.value;
  return value;
}

function isEmailAddr(email)
{
  var result = false;
  var theStr = new String(email);
  var index = theStr.indexOf("@");
  if (index > 0)
  {
    var pindex = theStr.indexOf(".",index);
    if ((pindex > index+1) && (theStr.length > pindex+1))
	result = true;
  }
  return result;
}

function validRequired(formField,fieldLabel)
{
	var result = true;
	
	if (formField.value == "")
	{
		alert('Gelieve een waarde te geven voor het "' + fieldLabel +'" veld.');
		formField.focus();
		result = false;
	}
	
	return result;
}

function allDigits(str)
{
	return inValidCharSet(str,"0123456789");
}

function inValidCharSet(str,charset)
{
	var result = true;

	// Note: doesn't use regular expressions to avoid early Mac browser bugs	
	for (var i=0;i<str.length;i++)
		if (charset.indexOf(str.substr(i,1))<0)
		{
			result = false;
			break;
		}
	
	return result;
}

function validEmail(formField,fieldLabel,required)
{
	var result = true;
	
	if (required && !validRequired(formField,fieldLabel))
		result = false;

	if (result && ((formField.value.length < 3) || !isEmailAddr(formField.value)) )
	{
		alert("Gelieve een geldig emailadres in te vullen.");
		formField.focus();
		result = false;
	}
   
  return result;

}

function validNum(formField,fieldLabel,required)
{
	var result = true;

	if (required && !validRequired(formField,fieldLabel))
		result = false;
  
 	if (result)
 	{
 		if (!allDigits(formField.value))
 		{
 			alert('Please enter a number for the "' + fieldLabel +'" field.');
			formField.focus();		
			result = false;
		}
	} 
	
	return result;
}


function validInt(formField,fieldLabel,required)
{
	var result = true;

	if (required && !validRequired(formField,fieldLabel))
		result = false;
  
 	if (result)
 	{
 		var num = parseInt(formField.value,10);
 		if (isNaN(num))
 		{
 			alert('Please enter a number for the "' + fieldLabel +'" field.');
			formField.focus();		
			result = false;
		}
	} 
	
	return result;
}


function validDate(formField,fieldLabel,required)
{
	var result = true;

	if (required && !validRequired(formField,fieldLabel))
		result = false;
  
 	if (result)
 	{
 		var elems = formField.value.split("/");
 		
 		result = (elems.length == 3); // should be three components
 		
 		if (result)
 		{
 			var day = parseInt(elems[0],10);
  			var month = parseInt(elems[1],10);
 			var year = parseInt(elems[2],10);
			result = allDigits(elems[1]) && (day > 0) && (day < 32) &&
					 allDigits(elems[0]) && (month > 0) && (month < 13) &&
					 allDigits(elems[2]) && ((elems[2].length == 2) || (elems[2].length == 4));
 		}
 		
  		if (!result)
 		{
 			alert('Please enter a date in the format DD/MM/YYYY for the "' + fieldLabel +'" field.');
			formField.focus();		
		}
	} 
	
	return result;
}

//verschillende forms controleren
function validateForm(theForm)
{
	
	if (!validRequired(theForm.Bedrijf,"Bedrijf"))
		return false;
	if (!validRequired(theForm.Naam,"Naam"))
		return false;
	if (!validRequired(theForm.Functie,"Functie"))
		return false;
	if (!validRequired(theForm.Adres,"Straat + nr"))
		return false;	
	if (!validRequired(theForm.Postnummer,"Postcode"))
		return false;
	if (!validRequired(theForm.Gemeente,"Plaats"))
		return false;
	if (!validRequired(theForm.Telefoon,"Telefoon"))
		return false;
	if (!validRequired(theForm.Fax,"Fax"))
		return false;
	if (!validEmail(theForm.Email,"Email"))
		return false;
		
		return true;
}