Change focus from Year Month Day

[iago]

I have three input fields

<input type ="text" name="year" maxlength="4">

When the user has finished inputting the year, I want the cursor to go automatically to the month then the day.

<input type ="text" name="month" maxlength="2">

<input type ="text" name="day" maxlength="2">

I'm sure there are load sof code out there, I cannot find the right google search term to find it

[WyCnet]

You will have to trap each keystroke, and preferrably retain only the numeric ones for the year. When a valid year is entered, switch the focus to the month field, blurring the year text box.

That is the direction to take, the code, well...