Iphone Trigger Keyboard In Input Field (html / Javascript)

I am trying to set a few input field connectd to each other. in the 1st field you can enter 3 digit in the 2nd field you can enter 3 digit in the 3rd field you can enter 4 digits

Solution 1:

An element.focus() should show the keyboard. You must be doing something wrong. Additionally if all your input / text areas are in a form element it should auto advance to the next element. You can also use element.blur() to hide the keyboard.