function isNumeric(keyCode)
{
    return ((keyCode >= 48 && keyCode <= 57) || keyCode == 8)
}

function isAlpha(keyCode)
{
    return ((keyCode >= 65 && keyCode <= 90) || keyCode == 8)
}

function isAlphaNumeric(keyCode)
{
    return ((keyCode >= 48 && keyCode <= 57) || (keyCode >= 65 && keyCode <= 90) || keyCode == 8)
}