function checkdateFormat(date)
{
	if (date.value == '' && date.id.indexOf('not_null=0') >= 0) return true;

	if ( 	(date.value.substring(0,2) <= '00') 
		|| 	(date.value.substring(0,2) >  '31') 
		||	(date.value.substring(3,5) <= '00')
		||	(date.value.substring(3,5) >  '12')
		||	(date.value.substring(6)   <= '1900')
		||	(date.value.substring(6)   >  '2100')
		||	(date.value.substring(2,3) != '-')
		||	(date.value.substring(5,6) != '-')		
		)
	{
		alert ("Datum Formaat Foutief");
		return false;
	}	
	return true;
}

function checktimeFormat(time)
{
	if (time.value == '' && time.id.indexOf('not_null=0') >= 0) return true;

	if ( 	(time.value.substring(0,2) <  '00') 
		|| 	(date.value.substring(0,2) >  '23') 
		||	(date.value.substring(3,5) <  '00')
		||	(date.value.substring(3,5) >  '59')
		||	(date.value.substring(6)   <  '00')
		||	(date.value.substring(6)   >  '59')
		||	(date.value.substring(2,3) != ':')
		||	(date.value.substring(5,6) != ':')		
		)
	{
		alert ("Tijd Formaat Foutief");
		return false;
	}	
	return true;
}

function checkForm (form)
{
	var elements = form.elements;
	for (var i = 0; i < elements.length; i++) 
	{
        //alert(elements[i].id);	
		if (	(elements[i].value == '') 
			&& 	(elements[i].id.indexOf('not_null=0') < 0)
			&& 	(elements[i].type != 'hidden')) 
		{
			alert (elements[i].name + ' Leeg');
			return false;
		}
		if (	(elements[i].id.indexOf('email') >= 0)
			&& ((elements[i].value.indexOf('@') < 0 ) || (elements[i].value.indexOf('.') < 0 )))
		{
			alert (elements[i].name + ' is geen geldig e-mail adres');
			return false;
		}
	}
	return true;
}

function checkStock (form)
{	
	var elements = form.elements;
	var stock, aantal,naam;
	for (var i = 0; i < elements.length; i++) 
    {        
        if (elements[i].id.indexOf('Stock')>=0) 
        {
            stock=elements[i].value;
            //alert(stock);
            naam =elements[i].id;
            //alert(naam); 	
        }    
        else if (elements[i].id.indexOf('Aantal')>=0) 
        {
            aantal=elements[i].value;
            if ((stock-aantal)<0) 
            {
                //alert (elements[i].name + ' ' + i);
                alert (naam + ' is niet toereikend');
                return false;
            }     
        }
        
	}
	return true;
}

function popupw(mypage,h,w,identifier, scroll, full, toolbar)
{
    var winl = (screen.width - w) / 2;
    var wint = (screen.height - h) / 3;
    winprops = 'height='+h+',width='+w+',top='+wint+',left='+winl+',fullscreen='+full+',resizable=yes,status=no,toolbar='+toolbar+',scrollbars='+scroll;
    win = window.open(mypage, identifier, winprops);
    if (parseInt(navigator.appVersion) >= 4) { win.window.focus(); }
}