we need to create a form asking the clients for their age. Is there any way to create a field where you can only fill in numbers - maybe only 4 numbers like 1976 or 2011. Second alternative could be date. It would be perfect if I could limit the number - something like "not lower than 1800 and not higher than 2012" to prevent invalid numbers.

I can create question with drop down list, but creating a list of all possible years would be stupid and incomfortable to choose from.

thanks much