function checkzoeken() {

	if (document.zoeken.trefwoord.value.length < 3) {
		alert("U dient minimaal drie karakters in te voeren om te zoeken.");
		document.zoeken.trefwoord.focus();
		return false;
	}
	//document.zoeken.submit.disabled = true;
	return true;
	
}

function postcode_regio() {

	if (document.regionaal.postcode.value.length != 4) {
		alert("U dient vier karakters in te voeren om te zoeken op postcode.");
		document.regionaal.postcode.focus();
		return false;
	}
	
}

function number_format (number, decimals, decsep, trim) {
	
	var exponent 		= "";
	var thousands_sep 	= ".";
	var decsep 			= decsep ? decsep : ".";
	var numberstr 		= number.toString ();
	var eindex 			= numberstr.indexOf ("e");
	
	if (eindex > -1) {
		exponent 		= numberstr.substring (eindex);
		number 			= parseFloat (numberstr.substring (0, eindex));
	}
	
	if (decimals != null) {
		var temp 		= Math.pow (10, decimals);
		number	 		= Math.round (number * temp) / temp;
	}
	var sign			= number < 0 ? "-" : "";
	var integer 		= (number > 0 ? Math.floor (number) : Math.abs (Math.ceil (number))).toString ();
	
	var fractional 		= number.toString ().substring (integer.length + sign.length);
	fractional 			= decimals != null && decimals > 0 || fractional.length > 1 ? (decsep + fractional.substring (1)) : "";
	
	if (decimals != null && decimals > 0) {
		for (i = fractional.length - 1, z = decimals; i < z; ++i) fractional += "0";
	}
	
	for (i = integer.length - 3; i > 0; i -= 3)	integer = integer.substring (0 , i) + thousands_sep + integer.substring (i);
	
	return sign + integer + (parseInt(fractional.replace(decsep, "")) == 0 && trim ? decsep +"-" : fractional.replace(/,([0-9]{2})0$/, ",$1")) + exponent;
	
}