function CheckStr(userInput,userOutput,userLength)
{
        StrLen = userInput.value.length;
        if (StrLen > userLength )
                {
                        userInput.value =
userInput.value.substring(0,userLength);
                        StrLeft = 0;
                }
        else
                {
                        StrLeft = userLength - StrLen;
                }
        document.getElementById(userOutput).innerHTML = eval("StrLeft");
}