function GetDaysInMonth(Year, Month) { return new Date(Year, Month, 0).getDate() }

function IsEMail(Address) {
    var r = /[_a-zA-Z\d\-\.]+@[_a-zA-Z\d\-]+(\.[_a-zA-Z\d\-]+)+$/;
    return r.test(Address)
}

function IsDate(DateString) {
    var a = DateString.split('/');
    var b = false;
    var Length = a.length;
    if (Length == 2 || Length == 3) {
	    var m = a[0];
	    var d = a[1];
	    var oDate = new Date();
        var y = oDate.getYear();
        if (Length == 3) y = a[2];
	    if ((y < 100 || y >= 1900 && y <= 2999) && m >= 1 && m <= 12 && d >= 1 && d <= GetDaysInMonth(y, m)) b = true
    };
    return b
}

function Trim(String) { return String.replace(/(^\s*)|(\s*$)/g, ""); }
        
function TrimTextbox(Textbox) { Textbox.value = Trim(Textbox.value) }