function MaskPhone(str, textbox, loc, delim) {

    var keyCode = window.event.keyCode;
    var frm = document.forms[0];
    var country;

    //for all arrow keys	

    if (keyCode == 13 || keyCode == 8 || keyCode == 0 || keyCode == 39)
        return;

    if (frm.selCountry == null)
        country = "US";
    else
        country = frm.selCountry.value;

    if (country == "US") {
        if (keyCode >= 48 && keyCode <= 57) //digits
        {
            var locs = loc.split(',');
            for (var i = 0; i <= locs.length; i++) {
                for (var k = 0; k <= str.length; k++) {

                    if (k == locs[i]) {
                        if (str.substring(k, k + 1) != delim)
                            str = str.substring(0, k) + delim + str.substring(k, str.length)
                    }
                }
            }
            textbox.value = str;
            return;
        }
        else
            window.event.returnValue = null; // discard character
    }
    else {

        if (keyCode >= 48 && keyCode <= 57) //digits
            return;
        //for non US zipcodes allow " " or "-" or "(" or ")"	
        if (keyCode == 45 || keyCode == 32 || keyCode == 40 || keyCode == 41)
            return;
        else window.event.returnValue = null; // discard character
    }
}

function Letters() {
    var keyCode = window.event.keyCode;
    if ((keyCode > 64 && keyCode < 91) || (keyCode > 96 && keyCode < 123) || keyCode == 8)
        return;
    else window.event.returnValue = null;
}