// used by util tiles, like date.jsp

function clearFieldIfNotNumber(fieldName)
{
    var yearField = document.getElementById(fieldName);
    var numericChars = "0123456789";
    var strText = yearField.value;
    if ("" == strText)
    {
        return;
    }
    var nextChar;
    for (i = 0; i < strText.length; i++)
    {
        nextChar = strText.charAt(i);
        if (numericChars.indexOf(nextChar) == -1)
        {
            yearField.value = "";
            return;
        }
    }
}