How to link two text boxes so that text flows from one to the other.

In Adobe Acrobat XI Pro,  I have managed to link two text boxes with JavaScript.

I have deselected the "scroll long text" and selected auto text size.

I have entered the script into the "custom keystroke script"

if ( event.fieldFull || event.willCommit ) this.getField("Details2").setFocus();

Now my problem is this works for IE but I can't get it to work with adobe reader or pdf expert on iPad.

I need my forms to work with both, windows & ios.

Any suggestions?