var keylen = 4;

var keycodes = {
        0: true,
        8: true,
        13: true,
        37: true,
        39: true,
        46: true
    };
    
function checkPhone(frm) {
    var id = frm.code.value;
    return (id.length == keylen);
}

function checkKey(e) {
    var key = 0;
    var isCtrl = false;
    
	if (window.event) {
		key = e.keyCode;
		isCtrl = window.event.ctrlKey;
		
	} else if(e.which) {	    
		key = e.which;
		isCtrl = e.ctrlKey;
	}
	
	if (isNaN(key)) 
	    return true;
	
	// check for backspace or delete, or if Ctrl was pressed
	if (isCtrl || keycodes[key])
		return true;

	keychar = String.fromCharCode(key);

    var reg = new RegExp("[0-9]");
    return (reg.test(keychar));
}

function goClck() {
	var opener;
	var pinbox;
	
	setTimeout("clearFields()",1000);

	if (document.getElementById) {
		pinbox = document.getElementById('pincode');
	} else {
		pinbox = document.tf.pincode;
	}

	if (pinbox.value.length < 5) {
		window.alert("Ongeldige pincode ingevoerd");
		return false;
	} else {
		newWidth = screen.width;
		newHeight = screen.height - 30;
		
		opener = window.open('about:blank','paynlopener','toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=yes,resizable=yes,width='+newWidth+',height='+newHeight+',left=0,top=0');
	}
}

function clearFields() {
	if (document.getElementById) {
		document.getElementById('pincode').value = "";
	} else {
		document.tf.pincode.value = "";
	}
}