function trimAll(sString)
{
	while (sString.substring(0,1) == ' ')
	{
		sString = sString.substring(1, sString.length);
	}

	while (sString.substring(sString.length-1, sString.length) == ' ')
	{
		sString = sString.substring(0,sString.length-1);
	}

	return sString;
}

function checkForm()
{
	for(i = 0; i < document.forms[0].elements.length; i++)
	{
    	var trimmed = trimAll(document.forms[0].elements[i].value);

        if(!trimmed)
    	{
      		var b = true;
    	}
  	}

    if (b)
    {
    	alert("U bent een verplicht veld vergeten in te vullen!");
     	return false;
    }
    else
    {
     	return true;
    }
}

function checkSome(which)
{
	for(i = 0; i < which.length; i++)
	{
        if(!document.forms[0].elements[ which[i] ].value)
    	{
      		var b = true;
    	}
  	}

    if (b)
    {
    	alert("U bent een verplicht veld vergeten in te vullen!");
     	return false;
    }
    else
    {
     	return true;
    }
}